Synonyms sign
These are all words for an event, an action or a fact that shows that something exists, is happening or may happen in the future.
sign an event, an action or a fact that shows that something exists, is happening or may happen in the future: Headaches may be a sign of stress.
indication (rather formal) a remark or sign that shows that something is happening or what somebody is thinking or feeling: They gave no indication as to how the work should be done.
sign or indication?
An indication often comes in the form of something that somebody says; a sign is usually something that happens or something that somebody does.
symptom a change in your body or mind that shows that you are not healthy; a sign that something exists, especially something bad: Symptoms include a sore throat.
The rise in inflation was just one symptom of the poor state of the economy.
symbol a person, an object or an event that represents a more general quality or situation: The dove is a universal symbol of peace.
indicator (rather formal) a sign that shows you what something is like or how a situation is changing: the economic indicators
signal an event, an action or a fact that shows that something exists, is happening or may happen in the future: Chest pains can be a warning signal of heart problems.
sign or signal?
Signal is often used to talk about an event, action or fact that suggests to somebody that they should do something. Sign is not usually used in this way: Reducing prison sentences would send the wrong signs to criminals.
Patterns
a(n) sign/indication/symptom/symbol/indicator/signal of something
a(n) sign/indication/symptom/indicator/signal that…
a clear sign/indication/symptom/symbol/indicator/signal
an obvious sign/indication/symptom/symbol/indicator
an early sign/indication/symptom/indicator/signal
an outward sign/indication/symbol
to give a(n) sign/indication/signal