These words characterize personal qualities of people in whom one has great confidence. Trustworthy is the strongest word, implying that one¡¯s confidence is complete and profound: a trustworthy friend. Reliable suggests competence and consistency: A reliable judge is one who has a record of sound opinions. A reliable person can be counted on to do what he has promised or been told to do: a reliable baby-sister. When applied to things, reliable means adequate, serviceable or true; a reference book, for example, might be called reliable if the information it presents is accurate. Dependable is akin to reliable but is a little more subjective; reliable is often used of relationships based on service between superiors and inferiors, whereas dependable more often suggests an attitude of personal allegiance rather than one of honesty or thoroughness in the performance of a duty. One goes to a dependable person confident of receiving loyalty, support or aid: a dependable ally. When applied to things, dependable suggests stability and consistency of performance: a dependable weed-killer.

That which has been found reliable in the past is trusty , though it may not merit as much confidence a something trustworthy : a trusty prisoner; a trusty sword.

SEE; allegiance, sure, trust, truthful.