x

n

1. unknown, unknown factor or quantity, variable; question, big question, question mark, riddle, conundrum, puzzle, sphinx; mystery, obscurity, arcanum, secret, occult; mystery man, ghostly figure, faceless person, invisible man; unexplored territory, Latin, terra incognita.

adj

2. experimental, pilot, trial, hypothetical, drawing-board, in the trial stages; untested, untried, ready for the shakedown; new, novel, exploratory.

v

3.(on a ballot, examination etc.) choose, opt, select, name, pick one's choice, check, single out; vote for, cast a vote, elect, prefer, mark one's preference; mark, signify, indicate.

4. delete, cross out, strike out or over, scratch, blue-pencil, Print. dele, Inf. bleep; expunge, expurgate, bowdlerize, abridge, edit, cut, slash, butcher, kill; erase, blot out, rub out, take out, knock out.