base (nom)
Sens 1 : a fundamental principle, foundation,
groundwork. [source : OX]
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Sens 2 : the lowest part of someting, especially the part
or surface on which it rests or stands. [source : OAAD]
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Sens 3 : a main or important element or ingredient to
which other things are added. [source : OD]
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Sens 1 : to use something as the thing from which
something else is developed. [source : LG]
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Sens 2 : to place on (also upon) a foundation,
fundamental principle, or underlying basis. [source : OED]