Leaf venation patterns (leaf architecture) are integrally linked to ecology, function, and phylogeny. Within angiosperms, research has largely focused on understanding leaf architecture in dicotyledonous taxa, while monocots have been relatively neglected. However, monocots are a diverse group of ecologically and economically important plants, and standardizing their leaf venation pattern terminology is critical for synthesizing patterns in evolution, morphological disparity, and analyzing the fossil record. Monocot leaves are characterized by a closed venation system with all parallel veins converging at the apex and the presence of entire margins. Additionally, the majority (independently of their gross morphology) of monocot species have veins running parallel to the primary direction of lamina extension, with transversely-oriented veins (cross veins) connecting adjacent parallel veins. These parallel veins vary in thickness in repeated patterns, which we propose referring to as A-veins, B-veins, etc.; they are potentially homologous to primary, secondary, and tertiary veins in other angiosperms. Reticulate venation patterns occur in four separate orders of monocots: Alismatales, Dioscoreales, Liliales, and Asparagales. While some monocots (e.g. Dioscorea) possess a dicot-type pattern of reticulation, with a main branching vein and free-ending veins in aereoles, other ‘reticulate’ monocots have a distinctly different pattern where the reticulation is formed by anastomosing and irregular veins within the parallel and cross-vein network. In both cases we refer to these non-parallel and non-cross veins as “higher order.” We will present a standardized terminology and traits to describe and characterize monocot leaves. This new terminology will contribute in understanding the functional, ecological, and evolutionary significance of monocot venation features.