13-letter words containing a, c, o, i
- arachnephobia — Misspelling of arachnophobia.
- arachniphobia — Alternative form of arachnophobia.
- arachnivorous — Spider-eating.
- arachnoiditis — an inflammation of the arachnoid membrane
- arachnophobia — an abnormal fear of spiders
- arachnophobic — an abnormal or pathological fear of spiders.
- araeometrical — relating to araeometry
- arboriculture — the cultivation of trees or shrubs, esp for the production of timber
- arc of lowitz — a halo or arc of light, occurring infrequently, which extends diagonally downward from a 22° parhelion.
- archaelogical — Nonstandard spelling of archaeological.
- archaeologian — (archaic) An archaeologist.
- archaeologist — a specialist in archaeology, the scientific study of prehistoric peoples and their cultures by analysis of their artifacts, inscriptions, monuments, etc.
- archaeometric — relating to archaeometry
- archbishopric — the rank, office, or jurisdiction of an archbishop
- archeological — of or relating to archaeology.
- archeologists — archaeology.
- archidiaconal — of or relating to an archdeacon or his office
- archipelagoes — Plural form of archipelago.
- architectonic — denoting, relating to, or having architectural qualities
- arctic willow — a low-growing shrub, Salix arctica, of the tundra
- arcticologist — a person who specializes in arcticology.
- aridification — the process by which a humid region becomes increasingly dry, as by climatic change or human interference with the ecology.
- aristocracies — Plural form of aristocracy.
- aristocratism — the principles of aristocrats
- aristolochene — (organic compound) A bicyclic sesquiterpene produced by certain fungi.
- arsenous acid — a toxic white powder, As2O3, used to make other arsenic compounds, insecticides, and preservatives; white arsenic
- arthroconidia — Plural form of arthroconidium.
- arthroscopies — Plural form of arthroscopy.
- articulations — Plural form of articulation.
- arundinaceous — resembling a reed
- aryepiglottic — pertaining to or connecting the arytenoid cartilage and the epiglottis.
- ascension day — the 40th day after Easter, when the Ascension of Christ into heaven is celebrated
- ascensiontide — the ten days from Ascension Day to the day before Whit Sunday
- ascoli piceno — a town in E central Italy, in the Marches: capital of the Roman province of Picenum; site of the massacre of all its Roman citizens in the Social War in 90 bc. Pop: 51 375 (2001)
- ascorbic acid — Ascorbic acid is another name for vitamin C.
- associability — the condition of or the capacity to be associable or linked or related in thinking
- associateship — to connect or bring into relation, as thought, feeling, memory, etc.: Many people associate dark clouds with depression and gloom.
- associational — relating to association or alliance or an association, alliance or affiliation
- associatively — in an associative or connective manner
- associativity — the quality of being associative
- astacological — relating to astacology
- astrodynamics — the study of the motion of natural and artificial bodies in space
- astronautical — of or relating to astronautics or astronauts.
- astroparticle — (astrophysics) A subatomic particle of cosmic origin.
- astrophysical — Of or pertaining to astrophysics.
- at a discount — below the regular price
- atamasco lily — any of a genus (Zephyranthes) of bulbous plants of the lily family, with hollow stems, grassy leaves, and funnel-shaped flowers of yellow, pink, red, or purple-tinged white
- athletic shoe — a shoe designed to be worn for sports, exercising, or recreational activity, as racquetball, jogging, or aerobic dancing.
- atmospherical — pertaining to, existing in, or consisting of the atmosphere: atmospheric vapors.
- atomic energy — nuclear energy