A Dictionary of Linguistics and Phonetics David Crystal

learnability 271
In some distinctive feature approaches to phonology, the term ‘lateral’
is specifically opposed to non-lateral (i.e. sounds which do not have a lateral
release, as described above), these being postulated as two of the contrasts
needed in order to specify fully the sound system of a language. In Chomsky
and Halle’s theory (see Chomskyan), for example, ‘lateral’ is classified as a
cavity feature, along with nasal, under the specific heading of secondary
apertures.
lattice (n.) A concept from abstract algebra, sometimes applied in semantic
theory to model mereology (part/whole relations). A lattice is a structured
set in which every pair of elements has a ‘join’ (sum) as well as a ‘meet’ (or
‘product’), conforming to certain conditions. Sometimes the weaker notion of a
semi-lattice is used instead, requiring every pair of elements to have a sum but
not necessarily a product.
law (n.)
see sound change
lax (adj.) One of the features of sound set up by Jakobson and Halle (see
Jakobsonian) in their distinctive feature theory of phonology, to handle
variations in manner of articulation. Lax sounds are those produced with
less muscular effort and movement, and which are relatively short and indistinct,
compared to tense sounds (see tension). Examples are vowels articulated
nearer the centre of the vowel area (as in bit, put).
layer (n.)
see metrical grid
layering (n.) A term used by some linguists to refer to the successive hierarchical
levels in an immediate-constituent analysis. In tagmemic grammar,
it refers to the inclusion of a tagmemic construction within another
construction at the same level, as in the car in the road, where the phrase is
within a phrase. Here it contrasts with loopback and level-skipping.
lazy pronoun In grammar and semantics, a term sometimes used for a usage
(quite common in informal speech) where there is an imprecise match between
a pronoun and its antecedent; also called pronoun of laziness. For example,
in X wears her hat every day of the week. Y wears it only on Sundays, the it in
the second sentence should more precisely be hers. In such cases, the pronoun
is being interpreted as equivalent to a repetition of the antecedent, even though
it is not co-referential with it. See also paycheck sentence.
lead (n.) A term used in acoustic phonetics as part of the study of voiceonset
time variations in initial plosive consonants: voicing lead refers to
the occurrence of voicing before the plosive release (burst); it contrasts with
‘voicing lag’.
leaf node
see node
learnability (n.) A suggested defining property of human language (contrasting
with the properties of other semiotic systems), referring to the way any