便
biàn
plain
informal; suitable; convenient; opportune; to urinate or defecate; equivalent to 就[jiu4]: then; in that case; even if; soon afterwards
person (亻) + change (更) = whatever is easy and natural for a person
更 primarily contributes the sound biàn here; the person radical (亻) anchors the sense of human convenience or bodily ease. The character's meanings — from 'convenient' to 'relieve oneself' — all center on what is easy and natural for a person.
Words with 便
排便
pái biàn
to defecate
通便
tōng biàn
(of medicine or food) to relieve constipation; to promote bowel movement
通便剂
tōng biàn jì
(pharmacology) a laxative
逢人便讲
féng rén biàn jiǎng
to tell anybody one happens to meet
随便
suí biàn
as one wishes
灵便
líng biàn
quick
顺便
shùn biàn
conveniently
领便当
lǐng biàn dāng
see 領盒飯|领盒饭[ling3 he2 fan4]
不便
bù biàn
inconvenient
不便险
bù biàn xiǎn
travel insurance covering flight delay, baggage loss etc (abbr. for 旅遊不便保險|旅游不便保险[lu : 3 you2 bu4 bian4 bao3 xian3])
不成功便成仁
bù chéng gōng biàn chéng rén
to succeed or die trying (idiom)
不方便
bù fāng biàn
inconvenience