Ian Culverhouse has swooped to sign the highly-rated, left-sided 18-year-old as cover for injured duo Tom Leak and Zak Mills.
Mahovo, who has Emirates FA Cup and EFL Trophy appearances to his name for his parent club, enjoyed a loan spell at Step 3 earlier in the season with Long Eaton United.
He will wear squad number 16 during his time with the Pilgrims and is eligible to make his debut against Gloucester City on Saturday.