in practical terms; from a practical standpoint
Used to shift focus from theory to real-world application or concrete aspects.
In practical terms, this plan has many problems.
The theory is correct, but it's difficult in practice.
Compound of 実際 (じっさい, 'reality; practice') + 面 (めん, 'aspect; side') + で (particle indicating location or means). The exact historical derivation is uncertain, but the phrase is conventionally used to mean 'in practical terms'.