There is a total of 21196 clues beginning with si
- Signal "OK"
- Signal "yes" with one's head
- Signal 'OK'
- Signal 'yes'
- Signal 65 Across
- Signal a musician
- Signal a performer doesn't want to hear
- Signal a show's end
- Signal across the room
- Signal after a shipwreck
- Signal after an air raid
- Signal after tattoo
- Signal again, as an actor
- Signal agreement
- Signal agreement, in a way
- Signal amplifier
- Signal an actor
- Signal an OK
- Signal apparatus: Var
- Signal approval
- Signal as a conductor might
- Signal assent
- Signal at a pagoda, maybe
- Signal at a séance, maybe
- Signal at a seance
- Signal at Christie's
- Signal at sea
- Signal at Sotheby's
- Signal at sunrise
- Signal at the end of philosophy class?
- Signal before taps
- Signal bell
- Signal bell
- Signal boost, in a way
- Signal booster
- Signal boosts on Twitter, briefly
- Signal box controls
- Signal by bugle
- Signal by flapping
- Signal by hand
- Signal caller
- Signal callers: Abbr
- Signal carrier in the body
- Signal code made by flapping
- Signal code
- Signal consent
- Signal converter
- Signal Corps specialty
- Signal cry of a former N Y C gang
- Signal device in 36 Across
- Signal device
- Signal devices: Var
- Signal disturbance
- Signal enhancer
- Signal Ernie's buddy to step onstage?
- Signal event of Jan 1, 1863
- Signal fire
- Signal fires
- Signal first used in 1909
- Signal flag
- Signal flag
- Signal flags, at sea
- Signal flare
- Signal flare of W W I
- Signal flare
- Signal flares
- Signal for "a stitch in time"
- Signal for a change in direction?
- Signal for a fastball
- Signal for a getaway
- Signal for a good samaritan
- Signal for a parley with a foe
- Signal for a programmer's jump
- Signal for a scramble
- Signal for a swig
- Signal for aid
- Signal for an act to end
- Signal for an actor
- Signal for an actor
- Signal for attention
- Signal for dinner
- Signal for help
- Signal for help
- Signal for hurrah
- Signal for immediate assistance
- Signal for silence
- Signal for silence
- Signal for the next speech
- Signal for the USCG
- Signal from a marooned sailor
- Signal from a note passer
- Signal from a radar screen
- Signal from a sinking ship
- Signal from a third base coach, sometimes
- Signal from an empty stomach
- Signal from an impatient motorist
- Signal from offstage
- Signal from space
- Signal from Sparks
- Signal from the conductor