[1570–80; swelt(e)r + -y1; cf. sultry]This word is first recorded in the period 1570–80. Other words that entered Englishat around the same time include: assimilate, balloon, cartridge, repeater, split-y is a native English suffix of adjectives meaning “characterized by or inclined to”the substance or action of the word or stem to which the suffix is attached. Otherwords that use the affix -y include: dreamy, grouchy, juicy, rumbly