Answer: longest

AnswerCrossword Clue
LONGESTMost time-consuming
longestof great or specified length
longestfor a long time
longestLONG, far-extending
LONGESTType of yard in a Burt Reynolds flick
LONGEST"The ..... Day" (1962)
LONGESTBilly Joel "The ... Time"
LONGESTLike the papacy of Pius IX, after St. Peter
LONGESTLike the day of the summer solstice
LONGESTMost extended
LONGESTMost extensive
LONGESTMost enduring
LONGESTOf greatest duration
LONGESTMost protracted
LONGESTMost extended.
LONGESTWhat "antidisestablishmentarianism" is.
LONGESTTops in endurance
LONGESTGuinness superlative
LONGESTMost tedious
LONGESTExtended to the max
LONGESTMost likely to put you to sleep?