Synonym of lost in time (having happened so long ago that it is lost or forgotten).

Having happened or originated in a time so long ago that it has been completely forgotten or lost. / (science fiction) Lost during time travel.

A communications signal technique in which the transmission time is varied according to a pseudorandom sequence, useful in antijamming etc.

plural of screen time

(chess) A situation in which one or both players have very little remaining time on their clocks, therefore increasing the chance of inaccuracies or blunders being played as well as the risk of flagging.

plural of time period

plural of period of time

(law, formal, idiomatic) The determination of a term of years due to the passage of time, rather than the occurrence of a specific event.

plural of time-piece

Alternative spelling of timepiece