sign on

verb

signed on; signing on; signs on

intransitive verb

1

: to engage oneself by or as if by a signature

signed on to the new project

2

: to announce the start of broadcasting for the day

sign-on

ˈsī-ˌnȯn 

-ˌnän

noun

Synonyms of sign on

• sign up (for)
• join
• enter
• enroll (in)
• rejoin
• enlist (in)

Examples of sign on in a Sentence

I signed on for the crew team simply as a lark

Recent Examples on the Web

The former bakery and coffee shop had signs on its door Monday morning that alerted fans to its exit. — Jenna Thompson, Kansas City Star, 2 Nov. 2026

By then Ono had signed on to the artificial intelligence company Axiom Math as its founding mathematician. — Lyndie Chiou, Scientific American, 29 Oct. 2026

Google announced its new Universal Cart earlier this year, with brands including Nike, Sephora, Target, Ulta Beauty, Walmart, Wayfair and Shopify merchants such as Fenty and Steve Madden signed on to integrate. — Lauren Schuster, Miami Herald, 29 Oct. 2026

Even if the Gulf states overcome their internal divisions and sideline concerns about Houthi activity, Tehran and Washington could refuse to sign on. — Allison Minor, Foreign Affairs, 29 Oct. 2026

Word History

First Known Use

1879, in the meaning defined at sense 1

Rhymes for sign on

• anton
• argon
• axon
• baronne
• baryon
• baton
• boron
• buisson
• bygone
• capon
• cardon
• chiffon

Kids Definition

sign on

verb

(ˈ)sī-ˈnȯn, 

-ˈnän

1

: to hire oneself by or as if by a signature

signed on as a member of the crew

2

: to announce the beginning of broadcasting