Seemly means proper and fitting for the occasion. Not seemly, a seemly silence, seemly behaviour.
It judges against the setting rather than against morality, which is why unseemly haste is wrong in a place and not wrong in itself. It survives mostly in the negative — unseemly is far commoner than seemly. Note that the Norse behind it means fitting, from a root meaning to be suitable.
1adjectiveseemlyProper and fitting for the occasion.
“It would hardly be seemly for the mayor to turn up at a funeral in shorts.”
seemly is a quality of propriety.
Old Norse soemiligr means fitting, from a root meaning suitable. Seem comes from the same fittingness.
Old Norse
sœmiligr — seemly
Middle English
semly
English, today
seemly
From Middle English semly, semely, semelich, from Old Norse sœmiligr (“seemly”); equivalent to seem + ly. Cognate with Icelandic sæmilegur (“seemly, passable”), Danish sømmelig (“seemly”).
Etymology from Wiktionary, CC BY-SA