Terms are typically nouns or nominal phrases, with a few adjectives, adverbs, and verbs (see also Stolze 1999: 93);
The terminological unit, as opposed to the lexical unit, is typically but not exclusively a compound (noun), either a single-word compound or a multiword compound depending on languagetypological factors; phrasal groups are more common in some languages;
The form does not occur in the general language – it is a neologism (for example, ‘labellum’ in Botany);
The form occurs in the general language,14 that is, it does ‘double duty’ (Sager 1990: 19), but with a different denotation – it has been ‘resemanticised’ or ‘terminologised’, often through metaphorical extension (for example, ‘platform’ in Information Technology as opposed to the railway station); different grammatical and semantic patterns may support general-language/speciallanguage polysemic differences including the absence/presence of plurals (for example, ‘music’/Ø, ‘music’/‘musics’), compounding possibilities (for example, ‘bus driver’: ‘school bus driver’ versus ‘i2c bus driver’), modification possibilities (for example, ‘occasional student’: ‘very occasional student’ is acceptable in general language but not in the special language of UK Higher Education); restricted conjugation (for example, third person only); restricted semantic selection restrictions (for example, in the English legal system a solicitor may ‘brief’ a barrister, but not vice versa);
Terms are relatively more frequent in special-language texts in relation to closed-class words such as prepositions, articles, determiners, modal verbs, and so on, than open-class words in general-language texts are; that is, special-language texts, especially expert-to-expert texts, tend to be lexically denser (see also footnote 18);
Terms may include punctuation marks and numbers (for example, ‘3-(4-carboxybenzyl)-2-chloro-5-(1,2-dimethoxyethyl)terephthalic acid’);
Terms may be substituted by alternative designations in some domains (for example, by formulae in Chemistry and by symbols in Physics).
