Let fall something
verb
To drop something either accidentally or purposely.
She let fall her pen on to the table
Often appears as...
let fall a tear
let fall a word
Definition 1 of 2
Pro Tip 1/3Physical Action
Refers to the physical act of releasing an object, intentionally or by mistake. 
He let fall the glass, and it shattered on the floor.
Pro Tip 2/3Subtle Clue
May suggest giving a hint or piece of information in a discreet or careful way. 
During the game, she let fall clues that helped us solve the mystery.
Pro Tip 3/3Emotional Expression
Used figuratively, can indicate the release of emotions or tears. 
Overwhelmed with joy, he couldn't help but let fall tears of happiness.