What's the difference between lexicon and seme?

Lexicon

Definition:

(n.) A vocabulary, or book containing an alphabetical arrangement of the words in a language or of a considerable number of them, with the definition of each; a dictionary; especially, a dictionary of the Greek, Hebrew, or Latin language.

Example Sentences:

(1) The period of 1924-1985 can be viewed as a repetition of the period between 1840-1890 in terms of the evolution of the place of pyromania in the lexicon of psychiatry, of its existence as a disease entity, and of its implications for personal responsibility for destructive acts.
(2) Three experiments were conducted to show that phonological encoding is typical for visually-presented letter strings, and that an interactive activation model with a phonological route to the mental lexicon accounts adequately for the word-superiority effect.
(3) Burnham said “a language of xenophobia has entered the lexicon” of British politics and that many politicians were flirting with racism.
(4) Spread of activation through the lexicon was measured in complementary automatic (low probability) priming experiments.
(5) A trauma registry has been created containing lexicons of terms arranged to foster the adoption of standardized and extensible terminology for the nature and mode of injury.
(6) The lexicon of conflict in a place such as Kashmir engenders normalisation of even the most ghastly thing.
(7) Results suggest that the morphological constituents of complex words are available in some word recognition tasks and that morphological knowledge is represented in the speaker's lexicon.
(8) For the svengali of mediocrity decreed that every year would culminate in the release of a single from the winner of his X Factor, and that this contribution to the lexicon would dutifully top the charts.
(9) The lexicon for most retailers runs from impulse buy to splurge to treat; they prefer us to wander the aisles with our eyes wide open and our minds shut tight.
(10) In addition, they had extreme difficulty in naming nonwords, which in terms of the dual-route model for word recognition indicates impairment in the indirect route to the lexicon.
(11) While previous research has demonstrated that the number of meanings associated with a word exerts a powerful influence on the internal lexicon of normals, the results of this study suggest that brain damage resulting in aphasia does not disrupt this semantic organization.
(12) The prime minister seemed to object to Marr raising the matter, saying this was "the sort of question that is all too often entering the lexicon of British politics".
(13) The “Great Cannon” has entered the cyberwar lexicon alongside the “Great Firewall of China” after a new tool for censorship in the nation was named and described by researchers from the University of Toronto.
(14) "Transphobic" even seems to have entered the lexicon at the Daily Mail, which is quite something.
(15) These features, it is argued, indicate the disconnection between two intact lexicons: the semantic and the phonological.
(16) The neighbourhood analyses provide a number of insights into the processes of auditory word recognition in children and the possible structural organization of words in the young child's mental lexicon.
(17) As an issue, poverty is to vanish, no longer a target or a word in the Conservative lexicon.
(18) It is suggested that this pattern is more easily explained in terms of compensatory mechanisms that access the reading lexicon than by use of the spelling system 'in reverse'.
(19) It is important that any expert witness or defendant be cognizant of this lexicon in order to avoid mistakes in or misinterpretations of their testimony.
(20) The Oxford boxing blue may have started to backtrack on his pledge , but with the term established in the diplomatic lexicon (well, David Cameron made a joke about it on Friday ) it might help delegates in Brisbane to know exactly what it means.