forsingen, equivalent to for- + sing. <span class="searchmatch">forsing</span> (third-person singular simple present <span class="searchmatch">forsings</span>, present participle <span class="searchmatch">forsinging</span>, simple past forsang, past participle...
prefixed to verbs with the sense of wearing or exhausting one's self. <span class="searchmatch">forsing</span> is to sing to exhaustion, forwander is to wander until weary, fortravel...