IPA: /ˈsaɪzəbl/
KK: /ˈsaɪzəbl/
Large in size or amount; considerable.
The company made a sizeable profit this year.
Sizeable → It is formed from "size" (from Old French *size*, meaning measurement or dimension) and "-able" (meaning capable of or suitable for). The word "sizeable" means capable of being measured or having a considerable size.
Think of 'size' as a measurement and remember that 'sizeable' means something that is capable of being measured as considerable.