Illustration of arch
- 1 round
- imp impost
- sp springer
- v voussoir
- k keystone
- ext extrados
- int intrados
- 2 horseshoe
- 3 lancet
- 4 ogee
- 5 trefoil
- 6 basket-handle
- 7 Tudor
1
: a typically curved structural member spanning an opening and serving as a support (as for the wall or other weight above the opening)
2
a
: something resembling an arch in form or function
especially
: either of two vaulted portions of the bony structure of the foot that impart elasticity to it
b
: something that has a curved shape like an arch
There was a slight arch in her eyebrows.
an arch in the cat's back
3
: archway
arched; arching; arches
1
: to cover or provide with an arch
A bridge arches the stream.
2
: to form into an arch
She arched her eyebrows.
1
: to form an arch
Trees arch above the promenade.
2
: to take an arch-shaped course
The ball arched toward the basket.
2
a
: mischievous, saucy
b
: marked by a deliberate and often forced playfulness, irony, or impudence
known for her arch comments
… decided to answer them by being teacherly in a sort of arch, Olympian way.—Gerald Early
archness
noun
1
: chief : principal
archfiend
2
: extreme : most fully embodying the qualities of the kind
archconservative
see archi-
: ruler : leader
matriarch
: having (such) a point or (so many) points of origin
endarch
arch·ness
ˈärch-nəs
plural -es
: the quality of being arch : playful slyness or roguishness
Did you know?
As a prefix, arch- appears in a number of titles referring to positions of superiority, such as archduke and archbishop; it can also mean "chief" (as in archnemesis) or "extreme" (archconservative). It comes from the Greek verb archein, meaning "to begin or to rule."
Cite this Entry
“Arch.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/arch. Accessed 20 Oct. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
