1.Lexicology is a branch of linguistics concerned with the vocabulary of the English language in respect to words and word equivalents.
2.A word may be defined as a fundamental unit of speech and a minimum free form; with a unity of sound and meaning, capable of performing a given syntactic function.
3.The morpheme is the smallest meanings linguistics unit of language, not divisible or analyzable into small forms.
4.Word-formation rules refer to the scope and methods whereby speakers of a language may create new words.
pounding or composition is a word-formation process consisting of joining two or more bases to form a new unit, a compound word.
6. Derivation may be defined as a process of forming new words by the addition of a word element, such as a prefix,suffix or combining form, to an already existing word.
7.Conversion is a word-formation process whereby a word of a certain word-class is shifted into a word of another word-class without the addition of an affix.
8.Motivation refers to the connection between word-symbol and its sense.
9.Metaphor is a figure of speech containing an implied comparison based on association of similarity, in which a word or a phrase ordinary and primarily used for one thing is applied to another, a process which often results in semantic change or figurative extension of meaning.
10.An idiom may be defined as a combination of two or more words which are usually structurally fixed and semantically opaque, and function as a single unit of meaning.。