With the feet preceding the rest of the body.(adverb)
In the manner of a deceased person (i.e., dead).(adverb)
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Use "feet first" in a sentence
"He arrived there feet first in one of those casual spaceman's somersaults that made an Earthbound mortal sick-physically and mentally with fear-and, looking up, was in time to see a ripple of bright flares along the flanks of the Gershmi light cruiser."
"He inched along feet first — unable to turn — trying to make as little noise as he could, though he was forced to stop once, preventing by sheer force of will the voiding of his stomach — jaw clenched against the rising bile, huffing like a wounded horse through his scarred nasal passages."
"With an unceremonious galumph, Ollie landed feet first up to his thighs in a mud hole next to the river."