The most common and most likely answer to this crossword clue is the 9 plus 4 letter word ANONYMOUS GIFT
I've seen this crossword clue in The Daily Telegraph
A
N
O
N
Y
M
O
U
S
G
I
F
T
Buddy explains!
The straight part
We know that "For the present it shall be nameless" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case for the present it shall be nameless = anonymous gift.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.