Klein Dictionary, מרמר

מרמר to become embittered.
    — Pi. - מִרְמֵר he caused bitterness to, embittered.
    — Pu. - מֻרֽמַר was[[illegible]] bittered.
    — Hithpalp. - הִתְמַרֽמֵר he embittered himself, became embittered, w[[illegible]]enraged. [Pilp. of מרר (= to be bitter). For other Pilp. verbs formed from ע״ע verbs cp. בזבז and words there referred to.] Derivatives: הִתְמַרְמְרוּת, מְמֻרְמָר.