1
general::
Phrase(s): sound someone out
to try to find out what someone thinks (about something). • I don’t know what Jane thinks about your suggestion, but I’ll sound her out. • Please sound out everyone in your department., Phrase(s): sound something out
to pronounce the letters or syllables of a word as a means of figuring out what the word is. (Usually said to a child.) • This word is easy, Bobby. Try to sound it out.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Seek the views or intentions of, as in We'd better sound out Mom about who's using the station wagon, or Let's sound out the staff before we decide which week we should close for vacation. This expression derives from sound meaning "to measure the depth of water by lowering a line or lead." It was transferred to other kinds of inquiry in the late 1500s, but out was not added for several centuries.
American Heritage Idioms