Webster's Collaborative New Word Dictionary - U
UFO (n.): in knitting, sewing, quilting etc.: an unfinished piece of work; a project left uncompleted.
unbanked: not having money deposited in a bank; also : not deposited in a bank.
underbanked: not using or having access to a full range of banking options.
unfathom (v): To come to understand (something mysterious, puzzling, or complicated); to solve (a mystery, etc.).
unterfirer (n.): in Jewish language: (at a Jewish wedding) a person who leads or accompanies the bride or groom to the chuppah. Occasionally also in... (see Oxford Dictionary).
use case: a use to which something (such as a proposed product or service) can be put.