The most common and most likely answer to this crossword clue is the 5 letter word STONE
I've seen this crossword clue in Independent
S
T
O
N
E
More clues leading to the result STONE
- Very old figure kept in step
- A very good man — I rock!
- Fully alert, one distant cry caught in the back, briefly
- Rock group worth breaking up? Not so far
- Diamond perhaps with slight, not light, colour
- Unable to see the way, I curse
- A weight, carrying coals to Newcastle? On the contrary
- Gem traced using Stoke-on-Trent city postcode
- Content of some 1As? Small number, next to road
- Gem of a joke by pious person
Buddy explains!

The straight part
We know that "Content of some 1As?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case content of some 1as? = stone.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 STONE mean?
STONE noun- A hard earthen substance that can form large rocks.
- A small piece of stone, a pebble.
- A gemstone, a jewel, especially a diamond.
- (plural: stone) A unit of mass equal to 14 pounds. Used to measure the weights of people, animals, cheese, wool, etc. 1 stone ≈ 6.3503 kilograms
- The central part of some fruits, particularly drupes; consisting of the seed and a hard endocarp layer.
- A hard, stone-like deposit.
- A playing piece made of any hard material, used in various board games such as backgammon, and go.
- A dull light grey or beige, like that of some stones.
- A 42-pound, precisely shaped piece of granite with a handle attached, which is bowled down the ice.
- A monument to the dead; a gravestone or tombstone.
- A mirror, or its glass.
- A testicle of an animal.
- A stand or table with a smooth, flat top of stone, commonly marble, on which to arrange the pages of a book, newspaper, etc. before printing; also called imposing stone.
- To pelt with stones, especially to kill by pelting with stones.
- To wall with stones.
- To remove a stone from (fruit etc.).
- To form a stone during growth, with reference to fruit etc.
- To intoxicate, especially with narcotics. (Usually in passive)
- To do nothing, to stare blankly into space and not pay attention when relaxing or when bored.
- To lap with an abrasive stone to remove surface irregularities.
- Constructed of stone.
- Having the appearance of stone.
- Of a dull light grey or beige, like that of some stones.
- Used as an intensifier.
- Willing to give sexual pleasure but not to receive it.
- As a stone (used with following adjective).
- Absolutely, completely (used with following adjectives).