The most common and most likely answer to this crossword clue is the 5 letter word TOKEN
I've seen this crossword clue in The Times
T
O
K
E
N
More clues leading to the result TOKEN
- Nominal fine received by a number
- Scotsman’s to know an indication
- Symbolic books reflecting breadth of knowledge
- Symbol adopted by Vladivostok entrepreneurs
- Nominal figure all right to be accepted
- Symbol given to three-quarters of county
- Sign showing where Barbie's affections go?
- Puff gets new symbol
- Reminder from 18?
- Evidence of ghetto Kenya largely erased
Buddy explains!

The straight part
We know that "Nominal" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case nominal = token.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 TOKEN mean?
TOKEN noun- Something serving as an expression of something else.
- A keepsake.
- A piece of stamped metal or plastic, etc., used as a substitute for money; a voucher that can be exchanged for goods or services.
- (sometimes figurative) Evidence, proof; a confirming detail; physical trace, mark, footprint.
- Support for a belief; grounds for an opinion.
- An extraordinary event serving as evidence of supernatural power.
- An object or disclosure to attest or authenticate the bearer or an instruction.
- A seal guaranteeing the quality of an item.
- Something given or shown as a symbol or guarantee of authority or right; a sign of authenticity, of power, good faith.
- A tally.
- A particular thing to which a concept applies.
- An atomic piece of data, such as a word, for which a meaning may be inferred during parsing.
- A conceptual object that can be possessed by a computer, process, etc. in order to regulate a turn-taking system such as a token ring network.
- A meaningless placeholder used as a substitute for sensitive data.
- (grammar) A lexeme; a basic, grammatically indivisible unit of a language such as a keyword, operator or identifier.
- (corpus linguistics) A single example of a certain word in a text or corpus.
- A characteristic sign of a disease or of a bodily disorder, a symptom; a sign of a bodily condition, recovery, or health.
- A livid spot upon the body, indicating, or supposed to indicate, the approach of death.
- Ten and a half quires, or, commonly, 250 sheets, of paper printed on both sides; also, in some cases, the same number of sheets printed on one side, or half the number printed on both sides.
- A bit of leather having a peculiar mark designating a particular miner. Each hewer sends one of these with each corf or tub he has hewn.
- A thin bed of coal indicating the existence of a thicker seam at no great distance.
- A physical object used for exchange between drivers and signalmen on single track lines.
- In a loom, a colored signal to show the weaver which shuttle to use.
- (Church of Scotland) A piece of metal given beforehand to each person in the congregation who is permitted to partake of the Lord's Supper.
- To betoken, indicate, portend, designate, denote
- To betroth
- To symbolize, instantiate
- Done as an indication or a pledge; perfunctory, minimal or merely symbolic.
- A minor attempt for appearance's sake, or to minimally comply with a requirement