- in the sticks
- instantane-ous
- informal pretty much
- inconstantly
- incomings
- illy-whacker
- incorrupt
- incumbency
- ince-ssantly
- in a bad way
- in the scud
- in a good mood
- imprimatur
- incorruptibility
- in many cases
- in days of yore
- in short order
- in the matter of
- in the nuddy
- interdicted
- in a dither
- in time of yore
- in good shape
- ire-versible
- in big
- in ancient Rome circus
- innovators
- in many instances
- itemized
- irregligious
- impressiveness
- in the back-blocks
- in rude health
- itsy-bitsy
- irreconci-lable
- in plenty
- in double quick time
- in abundance
- in flap
- in Queer Street
- invalided
- ill-conceived
- in the tall timbers
- iniquitous nefarious
- itch for
- itty-bitty
- intransigence
- in the ballpark of
- in good trim
- in a state
- in transports of delight
- indefatigability
- in a huff
- in fine fettle
- in jig time
- incurvation
- in a blue funk
- incomprehensible
- in a tiz-woz
- in a tiz
- intrinsically
- in a cold sweat
- in a lather
- in the boondocks
- insightful
- ill-thought-out
- informal you got it
- in trim
- in low spirits
- inherently
- in one's best interests
- in a tizz
- in a split scond
- in a tizzy
- informl chuck up
- in-effectual
- interstate
- in double-quick time
- ickle
- illywhacker
- in the twinkling of an eye
- in left field
- in no time at all
- instanter
- in every way
- in every respect
- in a paddy
- in a stew
- in a twitter
- is that a fact
- in the bag
- I never did
- I'll be blowed
- in a twit