The most common and most likely answer to this crossword clue is the 3 letter word ELT
I've seen this crossword clue in The Times
E
L
T
Buddy explains!
The straight part
We know that "pig" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case pig = elt.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ELT mean?
ELT verb- To injure (anything) by rough handling; handle roughly.
- To begrime; soil with mud; daub; smear.
- To work persistently or laboriously; be occupied in working (e.g. in the earth, rake among dirt, etc.).
- To meddle; interfere.
- To knead dough; stir dough previously kneaded to a proper consistency before baking.
- To become soft; become moist, as damp earth.
- One of the simplest or essential parts or principles of which anything consists, or upon which the constitution or fundamental powers of anything are based.
- A small part of the whole.
- The sky.
- (with "the") Atmospheric forces such as strong winds and rains.
- A place or state of being that an individual or object is best suited to.
- (usually in the plural) The bread and wine taken at Holy Communion.
- A group of people within a larger group having a particular common characteristic.
- A component in electrical equipment, often in the form of a coil, having a high resistance, thereby generating heat when a current is passed through it.
- One of the conceptual objects in a markup language, usually represented in text by tags.