in ‧ con ‧ sid ‧ er ‧ a ‧ ble /ˌɪnkənˈsɪd ə rəb ə l◂/ BrE AmE adjective
[ Word Family: adjective : ↑ considerable ≠ ↑ inconsiderable , ↑ considerate ≠ ↑ inconsiderate , ↑ considered ; verb : ↑ consider , ↑ reconsider ; noun : ↑ consideration , ↑ reconsideration ; adverb : ↑ considerably , ↑ considerately ≠ ↑ inconsiderately ]
not inconsiderable formal used to emphasize that something is large or important SYN considerable :
He has built up a not inconsiderable business empire.