tickler

n (dated infml 旧, 口 esp Brit) puzzle; problem 难题; 问题: an awkward little tickler to solve 需要解决的小难题.

thy, thyme, thyroid, ti, tiara, tibia, tic, tick, tick off, tick-tack, tick-tack-toe, tick-tock, ticker, ticker-tape, ticket, ticket office, ticket-office, ticking, ticking-off, tickle, ticklish, ticklishness, ticky-tacky, tidal, tidal wave, tidbit, tiddler, tiddly, tiddly-winks, tide, tide sb. over, tide-mark, tide-table, tideway, tidily, tidiness, tidings, tidy, tie, tie up,