deca
deca — prefix
1. added to the front of a word to show that something involves the number ten, esp
added to the front of a word to show that something involves the number ten, especially in the names of geometric shapes and figures
Salma drew a decagon, a flat shape with ten straight sides.
deca- + -gon = ten-sided shape
The museum displayed a decahedron, a solid figure with ten faces.
Mei counted the ten sides on the decagon shape that her teacher drew on the classroom whiteboard.
During the exam, Osei identified the decagon by counting its ten sides.
文法句型
deca- + noun
deca- + adjective
用法筆記
Frequently attached to nouns formed from Greek roots, especially in geometry. The shorter form 'dec-' appears before vowels (e.g., 'decagon' alongside 'decahedron').
常見錯誤
2. used before a unit of measurement in the metric system to mean ten times that un
used before a unit of measurement in the metric system to mean ten times that unit
A decaliter holds exactly ten liters of drinking water.
deca- + liter = unit of ten liters
Mathieu measured the field and found it was 0.3 decameters wide.
The recipe called for one decagram of salt for the dough.
In science class, Bilal checked the decameter markings on the running track.
- deci-
means one tenth, the inverse of deca-
文法句型
deca- + unit of measurement
deca- + meter/liter/gram
用法筆記
Only combines with standard metric base units (meter, liter, gram). Much less common in daily life than 'kilo-' (thousand) or 'centi-' (hundredth); the words 'decameter', 'decaliter', and 'decagram' appear mostly in textbooks and scientific contexts.
常見錯誤
deca — combining form
1. a word element that joins to the front of a technical term to describe something
a word element that joins to the front of a technical term to describe something whose internal structure consists of ten parts, members, or components — for example, a decapod is a creature with ten legs, and a decasyllabic line of verse has ten syllables
A decasyllabic line in a poem contains exactly ten syllables.
combining form + technical adjective (-syllabic)
In biology class, Yuki examined a decapod — a crustacean with ten legs — under the microscope.
combining form + noun (decapod = ten-legged creature)
Chinua trained for months to compete in the decathlon, a ten-event track and field competition, at nationals.
Elena studied the decasyllabic verse of Paradise Lost, noting how Milton built each line from exactly ten syllables.
文法句型
deca- + noun (technical)
deca- + adjective (technical)
用法筆記
Distinguish from the metric-system sense (prefix/2) — this combining form builds whole words describing a quantity or structure of ten, not a multiplier before a measurement unit. The same word 'decapod' can belong to either category depending on context: in zoology (having ten legs) vs. metric (not used).