Definition of "prelinguistic"

Look, you know, a grunted uh, I mean — which is what I use to fill up a silence to show I'm conscious while I'm groping for a word — is, like, prelinguistic language.

2009 January 11, William Safire, “Haircut”, in New York Times‎

Video a prelinguistic child with its mother. Show the recording to the mother and ask her which of the baby's noises and gestures she believes are intentional communication.

2013, Alison Wray, Aileen Bloomer, Projects in Linguistics and Language Studies, Third Edition, page 35