let in WordNet English dictionary

1. consent to, give permission
   "She permitted her son to visit her estranged husband"; "I won't let the police search her basement"; "I cannot allow you to see your exam"
   permit  allow  let  countenance 
   
2. make it possible through a specific action or lack of action for something to happen
   "This permits the water to rush in"; "This sealed door won't allow the water come into the basement"; "This will permit the rain to run off"
   let  allow  permit 
   
3. cause to move; cause to be in a certain position or condition
   "He got his squad on the ball"; "This let me in for a big surprise"; "He got a girl into trouble"
   get  let  have 
   
4. grant use or occupation of under a term of contract
   "I am leasing my country estate to some foreigners"
   lease  let  rent 
   
5. leave unchanged
   "let it be"
   let 
   
6. actively cause something to happen
   "I let it be known that I was not interested"
   let 
   

1. a serve that strikes the net before falling into the receiver's court; the ball must be served again
   let  net ball