French-English translations for aigre

sour
us
A possible development is a packaging material that changes colour when the milk in it turns sour or the food in it begins to perish. Une innovation possible est un matériau d’emballage capable de changer de couleur lorsque le lait qu’il contient devient aigre ou lorsque les aliments qu’il contient commencent à se détériorer. Lemons have a sour tasteDont drink that milk; its turned sour
acid
us
acid fruits or liquors

sharp
us
I keep my knives sharp so that they dont slip unexpectedly while carvingErnest made the pencil too sharp and accidentally stabbed himself with itA face with sharp features
tartI ate a very tart apple.He gave me a very tart reply.