noun
Colloquial, slightly childish or affectionate word for a corner or small out-of-the-way place. Often implies a cozy or hidden spot.
猫が部屋の隅っこで丸まっている。
The cat is curled up in the corner of the room.
子供たちは公園の隅っこで遊
The children were playing in a corner of the park.
隅 is the standard, neutral word for 'corner'. 隅っこ is a colloquial, diminutive form with a warmer, more informal feel.
Colloquial diminutive of 隅 (すみ, 'corner'), formed by adding the suffix っこ, which often adds a sense of smallness or endearment.