The most common and most likely answer to this crossword clue is the 3 letter word TWO
I've seen this crossword clue in The Daily Telegraph
T
W
O
More clues leading to the result TWO
- Company traditionally starts to trade with Orient
- Outline of waist, flipping round figure
- Prostitute grabbing prisoner got up as Henry IV
- Anything northern rejected for couple
- Time with old couple
- Form of three-way junction without a coupling
- What’s needed for match as well as broadcast
- Couple in ardent wooing
- Number in company excessively audible
- Prime pillock gives it away for nothing
Buddy explains!

The straight part
We know that "Cad" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cad = two.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 TWO mean?
TWO noun- The digit/figure 2.
- A two-dollar bill.
- A child aged two.
- A playing card featuring two pips.
- A numerical value equal to 2; this many dots (••).
- Describing a set or group with two elements.