credal or creedal/ʹkreedl/ adj

• insistent
• in situ
• insobriety
• in so far as
• insofar as
• insolation
• insole
• insolent
• insoluble
• insolvable
• insolvent
• in so many words
• in somebody's black books
• in somebody's confidence
• in somebody's corner
• in somebody's debt
• in somebody's favour
• in somebody's good/bad/black books
• in somebody's hair
• in somebody's midst
• in somebody's pocket
• insomnia
• insomuch as
• insomuch that
• in sooth