n.
    - a pale yellow oval citrus fruit with thick skin and fragrant, acidic juice. ▸a drink made from or flavoured with lemon juice. 
- the evergreen citrus tree which produces lemons. 
[Citrus limon.]
- a pale yellow colour.
- informal an unsatisfactory person or thing.
Derivative
  
  Etymology
  ME: via OFr. limon from Arab. līmūn; cf. lime2.