The most common and most likely answer to this crossword clue is the 3 plus 4 letter word EAT INTO
E
A
T
I
N
T
O
More clues leading to the result EAT INTO
- Use a lot of each colour filling in box
- Use cast during each round
- Consume some buckwheat in tortilla
- A shade over: European first to go through
- Nibble at some meat in tortilla
- Use up a colour in middle of neon
- Use up waste
- At Eton, I bunged up drain
- Use up each Spanish red
- Use up colour to separate each ring
Buddy explains!

The straight part
We know that "Waste" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case waste = eat into.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.