decorous adj.

Proto-Indo-European root meaning "to take, accept."

It forms all or part of: condign; dainty; decent; decor; decorate; decorous; deign; dignify; dignity; diplodocus; disciple; discipline; disdain; docent; Docetism; docile; docimacy; doctor; doctrine; document; dogma; dogmatic; doxology; heterodox; indignance; indignant; indignation; indignity; orthodox; paradox; synecdoche.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit daśasyati "shows honor, is gracious," dacati "makes offerings, bestows;" Greek dokein "to appear, seem, think," dekhesthai "to accept;" Latin decere "to be fitting or suitable," docere "to teach," decus "grace, ornament."

1680s, "in bad taste," from Latin indecorus "unbecoming, unseemly, unsightly; disgraceful," from in- "not, opposite of, without" (see in- (1)) + decorus "becoming, fitting, seemly, proper" (see decorous). Related: Indecorously; indecorousness (1670s).