A necessary condition of any semantic change, no matter what the cause, is some connection, some association between the old meaning and the new.
There are 2 kinds of association involved in different semantic changes: similarity of meanings and contiguity of meaning.
Similarity of meanings, or metaphor is a semantic process of associating2 referents, one of which in some way resembles the other.In other words, metaphor is a transference of meanings on the basis of similarity.
Eg.: the word "hand" got in the 16th century the meaning of a "pointer of a clock or a watch" because of the similarity of one of the functions performed by the hand. I.The words denoting parts of human body are widely used metaphorically in different languages, English included:
the legof the table, the footof the hill, the neckof a bottle, the tongueof flame, the mouthof a river, cave, the eyeof a needle, the earof a pitcher.
Allthese metaphorical meaningjare derived from the primary meaning. If a metaphor is based on physical properties it is called a simple metaphor.Simple metaphors can be classified according to the physical properties on the similarity of which they are based:
1) appearance or form: bridge - мост, переносица; nut - орех, голова; arm - рука, ветка. Alean person can be called "a skeleton", a tall and lean person is sometimes called "a lamp-post".
2) temperature: boiling hot - кипяток, горячий человек.
3) position - the head and the foot of a page.
4) colour. The names of some flowers and shrubs are commonly used to denote their colours: lilac - сирень, сиреневый; violet - фиалка, фиолетовый.
5) function of use: hand - рука, стрелка часов
6) movement: caterpillar-tractor - гусеничный трактор; foxtrot - бег лисы, фокстрот (танец); albatross - альбатрос (птица), аэроплан
II. The names of animals are often used metaphorically too to denote human qualities. Eg.: a bear (a surly person); a cat, a sheep, a horse, etc., a snake, lion, monkey, parrot etc. The word "horse" is used as a kind of prefix to indicate size or coarseness: horse - laugh - a loud laugh, Russian - ржание horse - play - грубое развлечение, игра
They are many phraselogical units containing the names of animals, insects, birds, etc.:
to rain cats and dogs - лить (о дожде) как из ведра to flog a dead horse - попусту тратить время dog-cheap - очень дешевый to have a bee in one's bonnet - быть с причудой
Different parts of speech can be used metaphorically: nouns, verbs, attributes, adverbs:
- What a skeleton you are!
- Don't monkey!
- He is a hot man.
- "Stop talking", - mother said hotly.
Metaphors can be trite,traditional (widely used in the language) and genuine(fresh, created by authors in their literary works). Medical texts, as a rule, contain trite metaphors.
7. Change of meaning: nature of semantic change: metonymy