n.
Pronunciation: ' lau ̇ (- ə )r, ' l ō - ə r
Variant: also lour \ ' lau ̇ (- ə )r \
Function: intransitive verb
Etymology: Middle English louren; akin to Middle High German l ū ren to lie in wait
Date: 13th century
1 : to look sullen : FROWN
2 : to be or become dark, gloomy, and threatening <an overcast sky lower ed over the village>