Green’s Dictionary of Slang

pimple in a bent n.

[SE pimple + bent, a grass-stalk]

something infinitesimally small.

[UK]Stanyhurst Of Virgil his Æneis Dedication to Dvnsayne: I could lay downe heere sundrye examples, were yt not I should bee thoght ouer curious, by prying owt a pimple in a bent.