ガス欠[gasuketsu] running out of gasoline (petrol)
欠けがえのない[kakegaenonai] irreplaceable
間欠[kanketsu] intermittence
金欠[kinketsu] running out of money
欠かす[kakasu] to miss (doing)

欠く[kaku] to chip
欠け[kake] fragment
欠ける[kakeru] to be chipped
欠員[ketsuin] vacancy
欠課[kekka] cutting class