There is a total of 21196 clues beginning with si
- Signal to clear the road
- Signal to combat pilots
- Signal to come
- Signal to come over
- Signal to enter
- Signal to from the pier, perhaps
- Signal to go
- Signal to go ahead
- Signal to go on, say
- Signal to go onstage
- Signal to leave
- Signal to leave a message
- Signal to leave, perhaps
- Signal to pause
- Signal to place a call
- Signal to proceed
- Signal to pull over
- Signal to record a message
- Signal to retire
- Signal to scramble
- Signal to slow
- Signal to snap
- Signal to start
- Signal to start partying?
- Signal to start playing
- Signal to start speaking, perhaps
- Signal to start talking
- Signal to stop
- Signal to stop playing
- Signal to stop, with "down"
- Signal to the auctioneer
- Signal to try to score
- Signal to with gestures
- Signal tone
- Signal tones
- Signal transmitter
- Signal used in the Navy or Army
- Signal via beeper
- Signal when to begin
- Signal with a gesture
- Signal with flags
- Signal with one's head
- Signal with the hands
- Signal withdrawal
- Signal word for the last letter
- Signal ___ (retweet, say)
- Signal, as a cab
- Signal, as a taxi
- Signal, as for an 18 Across
- Signal, in a sly way
- Signal, in a way
- Signal, in a way
- Signal, of sorts
- Signal-blocking device
- Signal-carrying, in a way
- Signal-code word
- Signal-detecting device
- Signal-enhancing audio equipment
- Signal
- Signaled
- Signaled boatswain style
- Signaled "goodbye"
- Signaled "hi" or "bye"
- Signaled "thumbs up"
- Signaled (a train) to stop
- Signaled a card holding
- Signaled a hack
- Signaled a passing ship
- Signaled a timeout, say
- Signaled an actor
- Signaled approval
- Signaled assent
- Signaled backstage, perhaps
- Signaled collusion
- Signaled completion, as a microwave
- Signaled for help
- Signaled from across the room, say
- Signaled goodbye
- Signaled hello or goodbye
- Signaled in a certain way
- Signaled offstage
- Signaled on "Jeopardy!"
- Signaled on stage
- Signaled one's arrival
- Signaled slyly
- Signaled to begin, as a conductor might
- Signaled to enter, say
- Signaled to speak
- Signaled to start
- Signaled to, as a taxi
- Signaled with a gesture
- Signaled with the hand
- Signaled, as a cab
- Signaled, as a taxi
- Signaled, in a sly way
- Signaled, in a way
- Signaled, in Charades
- Signaled, like a satellite
- Signaled, on "Jeopardy!"
- Signaled, on a quiz show