total lie; downright lie
Colloquial and emphatic; used to call something a complete, shameless lie.
That story is a total lie.
His excuse is obviously a downright lie.
Standard kanji-kana spelling.
Kana spelling is common in casual writing.
Rarely used kanji form.
嘘 (lie) + っぱち, an emphatic suffix. The suffix may be related to 八 (eight) used as a derogatory intensifier, but the exact derivation is uncertain.