In summary, dependant can be used for the noun in either British or American English, but dependent for either noun or adjective is a safe choice in American English.

Dependent definition: As an adjective, dependent describes something that relies on something else, whereas as a noun, it refers to someone who relies on another, primarily for financial support.

DEPENDENT meaning: 1. needing the support of something or someone in order to continue existing or operating: 2…. Learn more.

DEPENDENT definition: relying on someone or something else for aid, support, etc. See examples of dependent used in a sentence.

Definition of dependent adjective in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

To be dependent on something or someone means to need them in order to succeed or be able to survive.

relying on someone or something else for aid or support: dependent on her parents until she got a job. [ be + ~ + on + obj] conditioned or determined by something else;