The 21-year-old, who scored twice in four starts and four substitute appearances for the Pilgrims at the tail end of last season, is now back at the Jakemans Community Stadium for the 2023-2024 campaign.
He is registered and eligible ahead of the Bank Holiday weekend double-header against Warrington Town and Bishop’s Stortford.
Thorndike will wear squad number 33 during his second spell in Lincolnshire.