How to say "plausible" in Japanese

• もっともらしいCommon
  i-adjectiveCovers 'plausible' in the sense of sounding believable — an excuse, explanation, or story that seems convincing on the surface, sometimes with a hint that it may not be true. Often the direct choice for this sense.
  君きみの説明せつめいはもっともらしいが、筋すじがちっとも通かよってない。↗

  Your explanation sounds plausible, but it just doesn't hold water.
• 有力ゆうりょくJLPT N1approx.Common
  na-adjective, nounCovers 'plausible' in the sense of being likely or having strong support, as in a plausible theory, candidate, or explanation among alternatives. Its core meaning is 'strong; likely', so it is really about likelihood rather than surface believability.

Use 「もっともらしい」 for an explanation or story that sounds believable, and 有力 for a candidate, theory, or explanation that is strong or likely in a competitive evaluation.

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

• もっともらしいplausible
• まことしやかplausible (but untrue)
• 体のいいていのいいnice-looking
• 有力ゆうりょくstrong