身勝手|みがってmigatte[2]nakadaka (mid-high)

1. na-adjective, nounselfish; self-centred; egotistical
   彼かれの身勝手みがってな態度たいどに腹はらを立たてた。↗

   His selfish attitude put my back up.

• SynonymわがままNeutralThe most common word for selfish, wilful behaviour; fits children and adults. Nearly interchangeable with 「身勝手」, which stresses acting only for one's own convenience.
• Synonym勝手かってNeutralColloquial and wide-ranging: doing as one pleases or without permission, but also 'convenience' and even 'kitchen' — a broader word than 「身勝手」.
• Synonym自分勝手じぶんかってNeutralThe closest match to 「身勝手」 in meaning; the two are interchangeable and both are in common use.
• SynonymエゴイスティックWrittenLoanword meaning 'egoistic'. Rare even in written prose, and stiffer than 「身勝手」.
• Synonym利己的りこてきWrittenA formal, written term focused on self-interest, common in commentary and analysis; 「身勝手」 is more colloquial and describes concrete words and actions.
• Synonym得手勝手えてかってNeutralSame meaning as 「身勝手」 — acting only for one's own convenience — but rare in speech.
• Synonym手前勝手てまえがってNeutralAlso synonymous with 「身勝手」, stressing self-centred disregard of others, but rare in speech.
• Related一方的いっぽうてきNeutralOne-sided or unilateral; stresses ignoring the other party's situation, as in 「一方的な通告」 (a unilateral notice).
• Related野放図のほうずWrittenWritten word for brazen, unrestrained behaviour; stresses lack of limits, as in 「野放図な支出」 (wild spending), while 「身勝手」 stresses self-interest.
• Related自由勝手じゆうかってNeutralRare word for doing exactly as one likes; it stresses freedom from restraint and is not necessarily critical.
• Related我が強いががつよいNeutralStubborn and headstrong; stresses a strong will or sense of self, and does not necessarily imply selfishness.
• Antonym思いやりおもいやりNeutralAntonym: consideration and thoughtfulness for others — the very quality that 「身勝手」 behaviour ignores.
• Antonym献身けんしんNeutralAntonym: devotion or self-sacrifice — giving one's all for others, the opposite of 「身勝手」.
• Antonym利他りたWrittenAntonym: altruism, putting others' interests first. A written, formal term, the direct opposite of self-serving 「身勝手」.

For someone who acts only for their own convenience without regard for others, 「身勝手」 and 「自分勝手」 are the default choices and fully interchangeable. For a child's wilfulness say 「わがまま」; for one-sided decisions 「一方的」; in written analysis of self-interest, 「利己的」. The opposite quality is 「思いやり」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 自分じぶんだけの都合つごうで行動こうどうすること。わがまま。