acuto-, acut-, acuti-, acu-, -cusis; also, agu-

(Latin: sharp, to sharpen; point; needle, pin)

acicula (s) (noun), aciculae (pl)
A technical name for a slender needle-like body or part: The aciculae are the spines or prickles which some animals and plants are furnished with, or the needle-like crystals of certain minerals.
acicular (adjective), more acicular, most acicular
1. Needle-like; referring to a stout bristle or an extended and pointed structure: The slender leaves of pine trees, for example, are quite acicular.

A hummingbird has an acicular bill being long and narrow.
2. In metallurgy, when referring to cast iron or an alloy possessing a microstructure of pointed components: Some minerals showing acicular forms include mesolite, malachite, and gypsum.

acicular ice (s) (noun), acicular ices (pl)
In hydrology, freshwater ice made up of many long crystals; fibrous ice: satin ice: Such acicular ice contains air bubbles and has many long, needle-like crystals and hollow tubes in a layered arrangement.
aciculate (adjective), more aciculate, most aciculate
1. Descriptive of something marked with scratches or making such an appearance: When returning to her car, Susan noticed many aciculate scrapes on the side of it as if they were made with a knife.
2. Concerning a plant, an animal, or a crystal possessing needle-like parts: The arciculate fronds on the Christmas tree were quite sharp and hurt when touched!
aciculiform (adjective), more aciculiform, most aciculiform
Needle-shaped: The aciculiform stem was slender like a needle or a bristle.
aciculilignosa (s) (noun), aciculilignoses (pl)
An evergreen and deciduous needle-leaved vegetation: Sam and his wife were enthralled at the prospect of camping in the aciculilignosa woodland with coniferous trees and shrubs.
aciculine (adjective), more aciculate, most aciculate
Sharp and pointed like a needle; acicular: Sandy mended her skirt with an aciduline device that was so pointed it could prick her finger if she wasn't careful!
aciculite (s) (noun), aciculites (pl)
In mineralogy, needle ore: An aciculite is a metallic element that is a silver-white, reddish-tinged, brittle metallic element, such as lead and copper as seen in acicular or needle-shaped crystals.
aciculum (s) (noun), acicula (pl)
1. A needlelike spine or bristle: An aciculum is present in certain types of worms or flagellates.
2. A projecting cluster of bristles or setae: An aciculum is found in certain annelid worms, or is a fingerlike or handlike bristle seen in certain flagellate protozoa.
3. In zoology, one of the slender, sharp stylets embedded in the parapodia of certain annelid worms: Small needlelike appendages, or the aciculua, are lodged in the fleshy extremities of polychaetes.
4. A technical name for a slender needlelike body: The spines or prickles of some animals and plants are termed acicula, but also the needlelike crystals of certain minerals are called the acicula.
acuate (verb), acuates; actuated; acuating
To sharpen; to make pungent: Mr. Smith wanted to acuate the chili by adding a lot of peppers in order to spice up the taste.
acuate (adjective), more acuate, most acuate
Needle shaped, sharp-pointed. sharpened: Grace had all of her acuate pencils in her pencil case before going to school the next day.
acuation (s) (noun) (no pl)
The action of sharpening something; acuition: The process of acuation of his kitchen knives was necessary for Joe to prepare the vegetables and tomatoes for lunch.
acuclosure (s) (noun), acuclosures (pl)
The placement of pressure on a person's body: Acuclosure can be achieved with needles or with a therapist's hands to relieve pain in a patient's body.
acuity (s) (noun), acuities (pl)
Acuteness, keeness, as of thought or vision: Jane's grandmother's dementia caused her to lose her cognitive acuity.

Virginia's visual acuity became a real problem because she couldn't see the fine details of objects anymore.

acuity, acumen, acute
acuity (uh KYOO uh tee) (noun)
Related to "acute", with its sense of sharpness, acuity is used with reference to any human faculty and applied to any of the five senses as well as of the mind: Senator Mathews is thought to be a man of great political acuity.

There is no doubt that tiredness affects visual acuity.

acumen (uh KYOO muhn) (noun)
1. Mental sharpness, intelligence, sagacity: Susan Bretson is a woman who has considerable business and financial acumen.
2. Quickness in understanding and dealing with a situation; keen insight: The student contestant had the acumen to figure out which version of the homograph to spell correctly.
acute (uh KYOOT) (adjective)
1. Having a sharp point: Angles of less than 90 degrees are called acute angles.
2. Extremely severe and sharp; such as, an intense pain: Tyrone is suffering from acute appendicitis.
3. Keenly perceptive or discerning, ingenious: Einstein is said to have been a man of uncommonly acute intelligence.

Megan's natural acumen in science suggested that she had an acute sense of smell and good visual acuity.

Cross references of word families that are related directly, or indirectly, to: "sour, sharp": acerb-; aceto-; acid-; acies- (not "sour"); oxy-; pung- (not "sour").