a large white or brightly coloured flower with petals that curl back from the centre. There are many types of lily. 百合花 
tiger lilies 虎百合
Oxford Collocations DictionaryLily is used before these nouns:- pond
Word OriginOld English lilie, from Latin lilium, from Greek leirion.
Idioms
gild the lily
to cause something to be less good or beautiful than it already is by trying to improve it 画蛇添足；多此一举 Some people add a little brandy to the recipe but I feel this is gilding the lily. 有人在食谱中加了一点白兰地，但我觉得这使百合花烫了。