Many sulci are the product of a surface fold or junction, such as in the gums, where they fold around the neck of the tooth. The term sulcus is used in invertebrate zoology to describe folds, grooves, and boundaries, especially at the edges of sclerites or between segments. In botany and palynology, the surface morphology of seeds and pollen grains is termed sulcate if one or more sulci form major features.
Freebase(0.00 / 0 votes)Rate this definition: Gratitude. Gratitude, thankfulness, gratefulness, or appreciation is a feeling or attitude in acknowledgment of a benefit that one has received or will receive.
Noun. 1. appreciation-understanding of the nature or meaning or quality or magnitude of something; he has a good grasp of accounting practices. grasp, hold. discernment, savvy, understanding, apprehension-the cognitive condition of someone who understands; he has virtually no understanding of social cause and effect.