Function modeling of complex systems relies on predefined vocabularies of functions and flows. These vocabularies are usually developed in a top-down approach, i.e., by starting with a survey of existing systems and identifying their functions empirically. These vocabularies, while highly useful in manual modeling due to their expressive power and coverage, can be unsuitable for computerized modeling and reasoning, esp. for physics-based reasoning. To this end, this paper presents a physics-based vocabulary of function verbs developed using the bottom-up approach, where the need for the verbs is identified through a survey of physics phenomena involving operations on various energy forms allowed in physics. This survey results in a minimal set of only six verbs and two logical nodes that are proposed here. Each term is formally defined as object-oriented classes derived from more foundational classes proposed in prior research. The paper shows many applications of these terms, for modeling both simpler devices and more complex engineered systems. Collectively, this new vocabulary provides sufficient coverage over modeling needs and ensures models that are logically consistent and physics-wise valid.