shelty or sheltie/ʹshelti/ noun (pl shelties)

• insulate
• insulating tape
• insulation
• insulator
• insulin
• insult
• in sum
• insuperable
• insupportable
• insurance
• insure
• insured
• insurgence
• insurgency
• insurgent
• insurmountable
• insurrection
• insusceptible
• inswing
• int.
• intact
• intaglio
• intake
• in tandem
• intangible