In this matter, also, a dictionary goes so far as to list synonyms, and in some cases, actually adds a discussion to define the various limits.  For fuller, more careful discrimination a good book of synonyms should be consulted.  Except for some general consideration of words which everyone is certain to use or misuse, it is better to consult a treatise on synonyms when need arises than to study it consecutively.  In consultation the material will be fixed by instant use.  In study it may fade before being employed; it may never be required.

The subjoined paragraphs show entries in two different volumes upon synonyms: 

Adjacent, adjoining, contiguous.  Adjacent, in Latin, adjiciens, participle of adjicio, is compounded of ad and jacio, to lie near. Adjoining, as the word implies, signifies being joined together.  Contiguous, in French contigu, Latin contiguus, comes from contingo, or con and tango, signifying to touch close.

What is adjacent may be separated altogether by the intervention of some third object; what is adjoining must touch in some part; and what is contiguous must be fitted to touch entirely on one side.  Lands are adjacent to a house or town; fields are adjoining to each other; and houses contiguous to each other.

    CRABBE:  English Synonyms

Victory:  Synonyms:  achievement, advantage, conquest, mastery, success, supremacy, triumph. Victory is the state resulting from the overcoming of an opponent or opponents in any contest, or from the overcoming of difficulties, obstacles, evils, etc., considered as opponents or enemies.  In the latter sense any hard-won achievement, advantage, or success may be termed a victory.  In conquest and mastery there is implied a permanence of state that is not implied in victory. Triumph, originally denoting the public rejoicing in honor of a victory, has come to signify also a peculiarly exultant, complete, and glorious victory.  Compare conquer.  Antonyms:  defeat, destruction, disappointment, disaster, failure, frustration, miscarriage, overthrow, retreat, rout.

    FERNALD:  English Synonyms, Antonyms and Prepositions

Antonyms.  Notice that this second paragraph adds a new word-list—­antonyms.  To reinforce the understanding of what a thing is, it is desirable to know what it is not, or what its opposite is.  This kind of explanation or description is especially valuable to a speaker.  He can frequently impress an audience more definitely by explaining the opposite of what he wants them to apprehend.  At times the term is not the extreme opposite; it is merely the negative of the other.  Logically the other side of white is not white, while the antonym is the extreme black.