Example with Bulgarian: клещи (kleshti, "pincers"), гащи (gashti, "pants"), очила (ochila, "spectacles"), хриле (hrile, "gills"). Other languages, e.g. Serbo-Croatian...

somewhat unconventional or "unexpected" state of affairs, e.g. "Станишев носел очила, за да изглежда по-умен"—"[Prime Minister] Stanishev (says that) he wears...

gender of nouns that have no singular form can't be determined: финанси, очила, обуща. Some nouns have changed gender with time, for example the feminine...