dignified expression; solemn look; serious face
Describes a facial expression that appears dignified, solemn, or serious, often with a nuance of putting on an air of importance or gravity. The phrase もっともらしい itself means 'plausible' or 'specious', so the expression can imply a feigned seriousness.
He told a lie with a straight face.
During the meeting, the department head kept a solemn expression the whole time.
Kana spelling is standard; the kanji 尤もらしい顔 is rare and may not be recognized by many readers.
Kanji form using 尤; rarely used in modern writing and may cause confusion.
Derived from the adjective もっともらしい (plausible, specious) combined with 顔 (face). The adjective itself comes from もっとも (most, quite right) + らしい (seeming), literally 'seeming quite right'.