Also see definition of "Think" in Word Study
Study Dictionary
Think
THINK [ISBE]
THINK - think: The Old Testament often translates 'amar, "to say," meaning what one says to himself, and hence, a definite and clearly formulated decision or purpose (Gen 20:11; Nu 24:4; Ruth 4:4, etc.), illustrated by the, change made by the Revised Version (British and American) in the King James Version of Est 6:6, where "thought in his heart" becomes "said in his heart." In other passages, for chashabh, damah, or zamam, indicating the result of mental activity, as in an intention or estimate formed after careful deliberation (compare Ecclesiasticus 18:25); In the New Testament, most, frequently for dokeo, "to be of the opinion, "suppose," literally, "seem" (Mt 3:9; 6:7; Lk 10:36, etc.). Sometimes, for logizomai, "to compute," "reckon" (Rom 2:3, etc.); sometimes, for nomizo, literally referring to what attains the force of law (nomos), and then, "to be of the opinion"; or, for phroneo, implying a thought that is cherished--a mental habit, rather than an act (Rom 12:3; 1 Cor 13:11). The Greek hegeomai, "to consider," implies logical deduction from premises (Acts 26:2; Phil 2:6), while in Mt 1:20; 9:4, and Acts 10:19, enthumoumai, refers to the mental process itself, the thinking-out of a project, the concentration of the faculties upon the formation of a plan.H. E. Jacobs
Also see definition of "Think" in Word Study