Reliable (r-l-b'l), a.
Suitable or fit to be relied on; worthy of dependance or reliance; trustworthy. "A reliable witness to the truth of the miracles." A. Norton. The best means, and most reliable pledge, of a higher object. Coleridge. According to General Livingston's humorous account, his own village of Elizabethtown was not much more reliable, being peopled in those agitated times by "unknown, unrecommended strangers, guilty-looking Tories, and very knavish Whigs." W. Irving.
Note: Some authors take exception to this word, maintaining that it is unnecessary, and irregular in formation. It is, however, sanctioned by the practice of many careful writers as a most convenient substitute for the phrase to be relied upon, and a useful synonym for trustworthy, which is by preference applied to persons, as reliable is to things, such as an account, statement, or the like. The objection that adjectives derived from neuter verbs do not admit of a passive sense is met by the citation of laughable, worthy of being laughed at, from the neuter verb to laugh; available, fit or able to be availed of, from the neuter verb to avail; dispensable, capable of being dispensed with, from the neuter verb to dispense. Other examples might be added. -- Re*li"a*ble*ness, n. -- Re*li"a*bly, adv.
Shades of meaning
The word reliable has been sharply challenged, but seems to have established its place in the language. The objection to its use on the ground that the suffix -able can not properly be added to an intransitive verb is answered by the citation of such words as "available," "conversable," "laughable," and the like, while, in the matter of usage, reliable has the authority of Coleridge, Martineau, Mill, Irving, Newman, Gladstone, and others of the foremost of recent English writers. The objection to the application of reliable to persons is not sustained by the use of the verb "rely," which is applied to persons in the authorized version of the Scriptures, in the writings of Shakespeare and Bacon, and in the usage of good speakers and writers. Trusty and trustworthy refer to inherent qualities of a high order, trustworthy being especially applied to persons, and denoting moral integrity and truthfulness; we speak of a trusty sword, a trusty servant; we say the man is thoroughly trustworthy. Reliable is inferior in meaning, denoting merely the possession of such qualities as are needed for safe reliance; as, a reliable pledge; reliable information. A man is said to be reliable with reference not only to moral qualities, but to judgment, knowledge, skill, habit, or perhaps pecuniary ability; a thoroughly trustworthy person might not be reliable as a witness on account of unconscious sympathy, or as a security by reason of insufficient means. A reliable messenger is one who may be depended on to do his errand correctly and promptly; a trusty or trustworthy messenger is one who may be admitted to knowledge of the views and purposes of those who employ him, and who will be faithful beyond the mere letter of his commission. We can speak of a railroad-train as reliable when it can be depended on to arrive on time; but to speak of a reliable friend would be cold, and to speak of a warrior girding on his reliable sword would be ludicrous.