Mara; demon king
In Buddhism, the demon king who tempted Gautama Buddha and represents the forces that hinder enlightenment.
from Sanskrit māra
obstacle to enlightenment
Extended Buddhist use: anything that hinders spiritual progress, not just the personified demon.
Desire can become an obstacle to enlightenment.
Colloquial, often vulgar slang for the male organ. Usually written in katakana as マラ.
In Buddhism, Mara is considered a being that obstructs enlightenment.
That word means penis.
Standard kanji spelling for the Buddhist senses; also used for the colloquial sense, though kana is more common there.
Hiragana spelling also used for the colloquial sense.
Variant kanji spelling, less common than 魔羅.
Katakana spelling is usual for the colloquial 'penis' sense.
From Sanskrit māra, via Buddhist texts. The colloquial 'penis' sense is a slang extension, possibly from the idea of a 'troublesome' organ.