Medical Definition of infertile
: not fertile; especially : incapable of or unsuccessful in achieving pregnancy over a considerable period of time (as a year) in spite of determined attempts by heterosexual intercourse without contraception <infertile couples> <an infertile male with a low sperm count> <an infertile female with blocked fallopian tubes>—compare sterile 1
Seen and Heard
What made you want to look up infertile? Please tell us where you read or heard it (including the quote, if possible).