Is led a common noun

Answer 1

No, the word 'led' is the past tense of the verb to lead (pronounced 'leed').

• The common noun forms of the verb to lead are leader and the gerund, leading.

The word 'lead' is a verb, an adjective, and a noun.

• The noun 'lead' (pronounced 'leed') is a common noun as a word for position at the front; the amount or distance ahead; the principal role in a play; the person who has the principle role; a clue; a news story of chief importance; an insulated electrical conductor; a word for any lead of any kind.
• The noun 'lead' (pronounced 'led') is a common noun as a word for a heavy, bluish-gray, soft metal, the chemical element of atomic number 82; a general word for any form of this substance.

Answer 2

Yes, "LED" is a common noun because it refers to a type of light-emitting diode. It is not a proper noun specific to one particular LED.