The most common and most likely answer to this crossword clue is the 7 letter word PYRAMID
I've seen this crossword clue in Financial Times
P
Y
R
A
M
I
D
More clues leading to the result PYRAMID
- A system for selling Egyptian tomb
- Stuff in vacuous policy papers is a wonder
- Solid girl placed in sink to the left
- Figure Penny has fake army ID
- Woman in swim, making turn, is wondrous thing
- It's a wonder Biblical figure blocks sink up
- Solid girl blocking sink, pulled from the rear
- Put up journal page about minute tomb
- Virgin placed in lower recessed tomb, historically
- Low walls queen knocked over in burial place
Buddy explains!

The straight part
We know that "tomb" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case tomb = pyramid.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 PYRAMID mean?
PYRAMID noun- An ancient massive construction with a square or rectangular base and four triangular sides meeting in an apex, such as those built as tombs in Egypt or as bases for temples in Mesoamerica.
- A construction in the shape of a pyramid, usually with a square or rectangular base.
- A solid with triangular lateral faces and a polygonal (often square or rectangular) base.
- A medullary pyramid, the medial-most bumps on the ventral side of the medulla oblongata
- The game of pool in which the balls are placed in the form of a triangle at spot.
- A pyramid scheme.
- Alternative letter-case form of Pyramid. (a solitaire card game)
- The triangular layout of cards in the game of Pyramid.
- An approximately triangular headline consisting of several centered lines of text of increasing length.
- To build up or be arranged in the form of a pyramid.
- To combine (a series of genes) into a single genotype.
- To employ, or take part in, a pyramid scheme.
- To engage in pyramid trading.