(among word-game enthusiasts) Used to turn semordnilaps into palindromes.

Variety is what makes life interesting.

plural of is-a

(idiomatic) Something is not right, seriously amiss, especially when leading to suspicion of motive.

A process (for example, a court case) has been rigged behind the scenes and its outcome will not reflect true justice.

A home is not merely a building but requires inhabitants and a friendly atmosphere.