Build–in

to construct (especially something complex) by assembling and joining parts or materials:
to build a house.
to establish, increase, or strengthen (often followed by up):
to build a business; to build up one’s hopes.
to mold, form, or create:
to build boys into men.
to base; found:
a relationship built on trust.
Games.

to make (words) from letters.
to assemble (cards) according to number, suit, etc., as in melding.

to engage in the art, practice, or business of building.
to form or construct a plan, system of thought, etc. (usually followed by on or upon):
He built on the philosophies of the past.
to increase or develop toward a maximum, as of intensity, tempo, or magnitude (often followed by up):
The drama builds steadily toward a climax.
the physical structure, especially of a person; physique; figure:
He had a strong build.
the manner or form of construction:
The house was of modern build.
Computers.

a version of a program after compilation, typically an update to an existing version made before the program is released.
the process of producing a software build.
a new version or update of data in a database or on a website:
frequent, incremental builds of data.

Masonry.

a vertical joint.
the vertical dimension of a stone laid on its bed.

build in/into, to build or incorporate as part of something else:
to build in bookcases between the windows; an allowance for travel expenses built into the budget.
build up,

to develop or increase:
to build up a bank account.
to strengthen.
to prepare in stages.
to fill in with houses; develop into an urban area.
to praise or flatter.

verb
(transitive, adverb) to incorporate or construct as an integral part: to build in safety features
verb builds, building, built
to make, construct, or form by joining parts or materials: to build a house
(intransitive) to be a builder by profession
(transitive) to order the building of: the government builds most of our hospitals
foll by on or upon. to base; found: his theory was not built on facts
(transitive) to establish and develop: it took ten years to build a business
(transitive) to make in a particular way or for a particular purpose: the car was not built for speed
(intransitive) often foll by up. to increase in intensity: the wind was building
(cards)

to add cards to each other to form (a sequence or set)
(intransitive) to add to the layout of cards on the table from one’s hand

noun
physical form, figure, or proportions: a man with an athletic build
v.

In the United States, this verb is used with much more latitude than in England. There, as Fennimore Cooper puts it, everything is BUILT. The priest BUILDS up a flock; the speculator a fortune; the lawyer a reputation; the landlord a town; and the tailor, as in England, BUILDS up a suit of clothes. A fire is BUILT instead of made, and the expression is even extended to individuals, to be BUILT being used with the meaning of formed. [Farmer, “Slang and Its Analogues,” 1890]

n.

One’s physique, esp one’s figure or shape; bod: a husky build/ sexy build (1850s+)
A show whose earnings continue to increase: The revue was a build once word-of-mouth took hold (1950s+ Theater)
: It’s been a long build, but we can make our move now

Also, build into. Construct or include as an integral part; also, make automatic, concomitant, or inherent. For example, Frank Lloyd Wright liked to build in as much furniture as possible, not just bookcases but desks, tables, and the like, or We’ve got to build some slack into the schedule for this project. The literal usage referring to physical objects dates from the late 1920s. The figurative arose a decade or so later. Both are frequently used in past participle form, that is, built in.

build down
build in
build on
build on sand
build up