a sight for sore eyes

a Determinative

— A is used when the following word could be any of a certain type. Compare "A book I saw on the shelf" and "The book I gave you yesterday".

a Noun

— A is the first letter of the alphabet. The letter "a" comes before "b". — In some schools, an A is a very high grade. Ron got an A on his earth science test.

sight Noun

— Having sight is if you can see things. — A sight is something that people want to see. The Statue of Liberty is a popular sight in New York City. — A sight is something you see. — A sight is a device that is attached onto a weapon and it is for a person to look into to aim the weapon at an intended target.

sight Verb

— When you sight something, you see it. The farmers sighted something strange circling overhead.

for Preposition

— shows that something belongs to something else, or has a specific function This cake is for you. This is a net for catching fish. — For is used to show the reason for something He was angry, for he had never been called such terrible names before.

for Subordinator

— For introduces a clause with a subject and a to-infinitive It's not good for you to be too relaxed.

sore Noun

— A feeling of the muscles being very tired. My arm is sore after all the exercises.

eyes

— noun opinion or judgment in the eyes of the law I was wrong in her eyes