effector

noun

ef·​fec·​tor i-ˈfek-tər 

-ˌtȯr

plural effectors

1

: one that causes or brings about something

an effector of change

… sheer force of personality as an effector of discipline …

—Nathaniel Burt

We must be effectors of positive change by supporting the revised science standards in full …

—Emily Her

2

a

: a bodily tissue, structure, or organ (such as a gland or muscle) that becomes active in response to stimulation

Nerve cells (neurons) convey messages by electrical pulses that pass down the nerve fiber (axon) until they reach the junction with the next neuron or an effector such as a muscle.

—Steven Rose

Motor neurons carry out-going signals from the brain or spinal cord to the effector organs, namely the muscles and glands.

—Rita L. Atkinson et al.

b

: a molecule (such as an inducer or a corepressor) that activates, controls, or inactivates a process or action (such as protein synthesis)

What are the cell effectors that induce the physiologic turnover of sphingolipids? An obvious set of such effectors includes steroid hormones, tumor necrosis factor … and other chalones and suppressors of cell growth.

—Yusuf A. Hannun and Robert M. Bell

These … G-proteins, act as intermediates or transducers between the receptor for a given stimulus and the effector protein or enzyme that effects the response to the stimulus …

—Douglas Kline

c

: effector cell

… the macrophage has a dual role: that of antigen presentation, and, as an activated macrophage, that of an effector.

—Emil R. Unanue

Cell-surface receptors for immunoglobulins play a vital part in immunity by transporting immunoglobulins or by triggering immune effector functions after antibodies have bound to antigens.

—Alan F. Williams

3

robotics : end effector

Traditional changeovers are done during a shift, when an operator will unbolt an effector and rebolt another one in its place.

—Lauren Gibbons Paul

Examples of effector in a Sentence

Recent Examples on the Web

According to the company’s product page, Oli is a 165 cm-tall, 121 pounds (55 kg) humanoid robot with 31 degrees of freedom (DoF), supporting multiple end-effectors that enable it to perform tasks requiring fine motor control. —Kaif Shaikh, Interesting Engineering, 6 Oct. 2025

Humanoid loco-manipulation holds transformative potential for daily service and industrial tasks, yet achieving precise, robust whole-body control with 3D end-effector force interaction remains a major challenge. —IEEE Spectrum, 16 May 2025

Those proteins—called effectors—attack specific targets that collectively disable the host's defense responses and make the host more hospitable for its bacterial conqueror. —Beth Mole, ArsTechnica, 14 May 2025

Bumps that accommodate control effectors for flaps and so on are on the top of the wings, not the bottom. —Jacek Krywko, Ars Technica, 29 Mar. 2024

Genome-editing tools such as zinc finger nucleases and TALENs (transcription activator-like effector nucleases) already existed, but Crispr proved to be far more efficient, not to mention easier and cheaper to use. —Emily Mullin, WIRED, 19 Dec. 2023

Three things—receptors, an integrating center, and effectors—maintain homeostasis. —Eva Botkin-Kowacki, Popular Science, 28 June 2023

Technically, compressed air is not the only option, as a plasma effectors and others methods can also be used to manipulate air flow. —Sébastien Roblin, Popular Mechanics, 17 May 2023

In all, Foralumab induces many factors that impact improved tissue remodeling, induction of immune cells, and restriction of effector function, improving disease outcomes while fighting the virus to full strength. —William A. Haseltine, Forbes, 16 Mar. 2023

Word History

Etymology

effect entry 2 + -or entry 1 (after receptor)

First Known Use

1586, in the meaning defined at sense 1

Phrases Containing effector

• effector cell
• end effector

Rhymes for effector

• bisector
• collector
• connector
• corrector
• defector
• deflector
• detector
• director
• dissector
• ejector
• elector
• erector

Kids Definition

effector

noun

ef·​fec·​tor i-ˈfek-tər 

-ˌtȯ(ə)r

: a bodily part (as a gland or muscle) that becomes active in response to stimulation (as by a nerve)

Medical Definition

effector

noun

ef·​fec·​tor i-ˈfek-tər  -ˌtȯ(ə)r 

1

: a bodily tissue, structure, or organ (as a gland or muscle) that becomes active in response to stimulation

Unlike the motor pathways of the somatic nervous system, which usually include a single neuron between the brain or spinal cord and an effector, those of the autonomic system involve two neurons.

—John W. Hole

2

: a molecule (as an inducer, a corepressor, or an enzyme) that activates, controls, or inactivates a process or action (as protein synthesis or the release of a second messenger)

What are the cell effectors that induce the physiologic turnover of sphingolipids? An obvious set of such effectors includes steroid hormones, tumor necrosis factor … and other chalones and suppressors of cell growth.

—Yusuf A. Hannun and Robert M. Bell

3

: effector cell

… the macrophage has a dual role: that of antigen presentation, and, as an activated macrophage, that of an effector.

—Emil R. Unanue