底線

bottom line; the limit of what one is prepared to accept / (sports) baseline / (sewing) under thread / spy; informer; plant

(equivalent to 的 as possessive particle)

background / bottom / base / end (of the month, year etc) / remnants / (math.) radix / base

thread / string / wire / line / CL:條|条[tiao2],股[gu3],根[gen1] / (after a number) tier (unofficial ranking of a Chinese city)