#aperto

• Aperto — A musical term of performance direction indicating that a piece must be executed in an open, clear, broad, and bright manner. In a broader literary sense, it stems from foreign phrases meaning unfolding without restrictions or secrets (e.g., in aperto).
• Aperto libro — A Latin phrase (literally translated as 'with the open book') used in academic or literary environments to describe the action of translating, interpreting, reading, or analyzing a text on the spot, directly at first sight, without prior preparation, study, or consultation of dictionaries.
• Apertometer — A precision optical instrument or device used in physics and microscopy to measure the numerical aperture of an optical lens, particularly microscope objectives, thereby determining their light-gathering capacity and resolving power.