WordReference Random House Unabridged Dictionary of American English © 2026
in•fin•i•ti•val
(in′fin i tī′vəl),USA pronunciation adj.
Grammarof or pertaining to the infinitive.
in′fin•i•ti′val•ly, adv.
WordReference Random House Learner's Dictionary of American English © 2026- infinitive + -al1 1865–70
in•fin•i•tive /ɪnˈfɪnɪtɪv/USA pronunciation n. [countable]
adj. [before a noun]
WordReference Random House Unabridged Dictionary of American English © 2026- GrammarThis word is the name of a verb form that in many languages names the action of a verb but is separate from the verb; it may function as a noun, adjective, or adverb. It is often translated into English with the word "to'' before it:The Spanish infinitive hablar means "to speak.''
- This word, when referring to English verb forms, is used
- in some grammar books to mean "the root form of the verb;
the form that follows certain modal verbs, or that comes after (but does not include) the word to:''We use the infinitive without to after words like must and should, as in "We must go;
we should leave,'' where go and leave are the infinitives. - in this dictionary and in many grammar books, to mean "the word to, followed by the root form of the verb:''We can use the infinitive of the verb as the subject of a sentence; the phrase to err is the infinitive and is the subject of the sentence "To err is human.''
- in some grammar books to mean "the root form of the verb;
adj. [before a noun]
- Grammarconsisting of or containing an infinitive:an infinitive clause.
- In this book, the term root is used for the basic form of a verb, esp. the form that appears after the word to and in commands (compare imperative). The term infinitive is used in this book for the construction made up of to and a following root form of a verb. Thus, the word take is called the root, and the construction to take is called the infinitive.
in•fin•i•tive
(in fin′i tiv),USA pronunciation [Gram.]
n.
adj.
in•fin′i•tive•ly, adv.
n.
- Grammara verb form found in many languages that functions as a noun or is used with auxiliary verbs, and that names the action or state without specifying the subject, as French venir "to come,'' Latin esse "to be,'' fuisse "to have been.''
- Grammar(in English) the simple or basic form of the verb, as come, take, eat, be, used after auxiliary verbs, as in I didn't come, He must be, or this simple form preceded by a function word, as to in I want to eat.
adj.
- Grammarconsisting of or containing an infinitive:an infinitive construction. Abbr.:infin.
- Late Latin infīnītīvus indefinite, equivalent. to in- in-3 + fīnītīvus definite; see finite, -ive
- late Middle English 1425–75
'infinitival' also found in these entries (note: many are not synonyms or translations):