اِسْتَرْسَلَ (الشّعْرُ) to be long and flowing, be lank, hang loose, hang (down)

اِسْتَرْسَلَ (فِي): أطْلَقَ العِنَانَ لِعَوَاطِفِه إلخ، تَحَرّرَ مِنَ التّكَلّف، أفْرَطَ، تَمَادَى to let oneself go, be uninhibited or unrestrained, slacken the reins, act naturally or without affectation, be at ease; to abandon oneself (to), give oneself up (to); to indulge (in), give way (to one's desires, etc.); to go too far (in), be excessive (in)

اِسْتَرْسَلَ فِي الكَلامِ إلخ: أسْهَبَ to talk at great length about, elaborate on, enlarge upon, expatiate on, dilate on, dwell on