noun, adverb
fairly long time; a while
Refers to a moderately long but indefinite period, often around two hours or so. Can be used as a noun or adverbially.
ふたときほど待ったが、彼は来なかった。
I waited for a fairly long time, but he didn't come.
ふたときの休息をとる。
Take a fairly long rest.
noun
four-hour period
Archaic temporal unit equal to four hours, used in the old Japanese time system. Not used in modern Japanese.
昔の時刻では、ふたときは今の四時間にあたる。
In the old time system, ふたとき corresponds to four hours today.
ひととき means 'a short while' or 'a moment', whereas ふたとき implies a longer period, roughly twice as long.
Compound of 二 (ふた, 'two') and 時 (とき, 'time' or 'hour'). The reading ふたとき is a native Japanese reading (kun'yomi).