dlegh- / Indo-European roots
To engage oneself.European root found in Celtic, Germanic, Slavic, and possibly Latin.
a. play from Old English plegian, to exercise oneself, play;
b. pledge; frankpledge, replevin from Late Latin plevium (> Old French plevir, to pledge), pledge, guarantee;
c. plight2 from Old English pliht, danger, peril, from Germanic derivative noun *plehti-. a-c from Germanic *plegan, probably altered (by dissimilation) from *tlegan.
2. Zero-grade form *dl̥gh-. indulge from Latin indulgēre, to indulge, explained by some as from prefixed and suffixed stative form *en-dl̥gh-ē- (*en-, in; see en)
[Pokorny dhl̥gh- 271.]