Half has 12 different meanings across 5 categories:
one of two divisions into which some games or performances are divided: the two divisions are separated by an interval
"The crowd cheered loudly when the halftime whistle blew, signaling a break between the first and second halves of the soccer match."
One of two usually roughly equal parts into which anything may be divided, or considered as divided.
"She tore the napkin in half to use it for wiping her hands after dinner."
In plain English: A half is one of two equal parts that something has been cut into.
"Please cut that pizza in half."
Usage: Use "half" as a noun to refer to one of two equal portions of a whole object, such as eating half an apple or taking half the money. It functions as a singular countable noun that represents a specific division rather than a fraction of a larger number.
To halve.
"She decided to half the recipe since she was cooking dinner for just two people."
In plain English: To split something into two equal parts.
"The sun began to half the darkness when the clouds finally parted."
Usage: Use "half" as a verb only in informal contexts to mean dividing something into two equal parts, often followed by "it" or "them." Avoid using this form in formal writing where "halve" is the preferred standard term.
consisting of one of two equivalent parts in value or quantity
"a half chicken"
"lasted a half hour"
Consisting of a half (½, 50%).
"The recipe calls for exactly half a cup of sugar to make the batter sweet enough."
In plain English: Half means being divided into two equal parts, so you have only one of those two pieces.
Usage: Use half as an adjective to describe something divided into two equal parts or representing fifty percent of a whole, such as in a half-full glass. It typically appears before the noun it modifies to indicate that quantity.
In two equal parts or to an equal degree.
"After eating half of the pizza, I realized my roommate had already taken the other half without telling me."
In plain English: Half means doing something halfway or not all the way through.
"She half smiled when she heard the good news."
Usage: Use "half" as an adverb to modify verbs when indicating that an action is performed partially or incompletely, such as in "I half expected him to arrive." It describes the extent of the action rather than dividing a noun into two equal parts.
half past; A half-hour (30 minutes) after the last hour; i.e. 9.30="half (past) nine". (Not to be confused with #2)
"The meeting was scheduled for a quarter before ten, but I arrived at half past nine and found everyone already seated."
A call reminding performers that the performance will begin in thirty minutes.
"The stage manager blew her whistle to signal a half, letting the actors know their show would start in exactly thirty minutes."
The word "half" comes from Old English healf, which originally meant both "half" and "side." It traces its roots back to the Proto-Germanic language through earlier West Germanic forms.