(idiomatic) A persistent annoyance.

(idiomatic) The part of town that is not inhabited by the wealthy. An area where the working class, poor or extremely poor live.

Any turtle of the family Pelomedusidae, characterised by protecting its head by turning it to one side rather than, as other turtles do, withdrawing it into its shell.

Alternative spelling of sunny side up

(idiomatic) To act in the least risky manner in a situation in which one is uncertain about the consequences.

plural of thorn in someone's side

Mergus squamatus, an endangered species of merganser found in eastern Asia

(construction) An application wherein the waterproofing system and source of hydrostatic pressure are on opposite sides of the structure.

(construction) An application where the waterproofing systems and source of hydrostatic pressure are on the same side of the structural element.

(algebra) A subring which is both a left ideal and a right ideal. Commonly referred to simply as an ideal, but referred to as two-sided ideal for emphasis.