1. Somewhat long.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• longist,
• angish,
• engish,
• lenguish,
• longas,
• longin,
• langwish,
• luggish,
• lokoism,
• longfish,
• longgish,
• longishh,
• longwsie,
• lonkish,
• ponfish,
• yongish,
• ronyish,
• tougish,
• wingish,
• jingish

• long,
• longways,
• longs,
• longer,
• longwise,
• longing,
• longicorn,
• longest,
• lounges,
• anguish.

The adjective form of the word "longish" is "longish". The word itself is already an adjective that describes something as somewhat long or moderately long.

The plural form of the word "longish" is "longishes".

The singular form of the word "longish" is "longish" itself. "Longish" is an adjective and does not have a distinct singular form.