as·sump·tive \-(p)tiv\adjective Etymology: probably from (assumed) New Latin assumptivus, from Latin assumptus, past participle of assumere + -ivus -ive : assumed, assuming: as a.: taken as one's own < upstarts with their assumptive arms > b.: taken for granted or inclined to take for granted < assumptive beliefs > < the assumptive habits of her mind > c.: making undue claims < an assumptive person >