The Collaborative International Dictionary of English v.0.48:

Supple \Sup"ple\, v. t. [imp. & p. p. Suppled (s[u^]p"p'ld);
   p. pr. & vb. n. Suppling (s[u^]p"pl[i^]ng).]
   1. To make soft and pliant; to render flexible; as, to supple
      leather.
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            The flesh therewith she suppled and did steep.
                                                  --Spenser.
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   2. To make compliant, submissive, or obedient.
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            A mother persisting till she had bent her daughter's
            mind and suppled her will.            --Locke.
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            They should supple our stiff willfulness. --Barrow.
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