LENGTHY
extended, drawn-out, lengthy, prolonged, protracted
(adjective) relatively long in duration; tediously protracted; “a drawn-out argument”; “an extended discussion”; “a lengthy visit from her mother-in-law”; “a prolonged and bitter struggle”; “protracted negotiations”
Source: WordNet® 3.1
Etymology
Adjective
lengthy (comparative lengthier, superlative lengthiest)
Having length; long and overextended, especially in time rather than dimension.
Speaking or writing at length; long-winded.
Source: Wiktionary
Length"y, a. [Compar. Lengthier; superl. Lengthiest.]
Definition: Having length; rather long or too long; prolix; not brief; --
said chiefly of discourses, writings, and the like. "Lengthy
periods." Washington. "Some lengthy additions." Byron. "These would
be details too lengthy." Jefferson. "To cut short lengthy
explanations." Trench.
Source: Webster’s Unabridged Dictionary 1913 Edition