Prefix · bone · skeletal
Means "bone": osteoporosis, osteology, osteopathic, osteoblast, osteoarthritis.
Written by Bryan López, English teacher · Updated
Osteo- comes from Greek "osteon" (bone) and appears mainly in medical and anatomical vocabulary. Osteoporosis = weakening of bones (osteo- + poros = pore + osis = condition); osteology = scientific study of bones; osteopath = a practitioner who uses skeletal manipulation techniques; osteoblast = a cell that forms new bone; osteoarthritis = arthritis that wears down joint cartilage. The Spanish equivalent is the same prefix: osteo-.
The adult skeletal system has 206 bones, and osteo- appears across all specialties that study it. Osteology covers the complete study of the skeletal system. Osteoporosis mainly affects post-menopausal women as bones lose density and become fragile. Osteoblasts (bone builders) and osteoclasts (bone dissolvers) work together in continuous bone remodelling. More advanced terms include osteocalcin and osteogenesis imperfecta.
Combines with Greek roots in medical and anatomical vocabulary:
Pronunciation: /ˈɒs.ti.oʊ/. Identical Spanish cognates: osteoporosis (osteoporosis), osteología (osteology), osteopatía (osteopathy), osteoartritis (osteoarthritis), osteoblasto (osteoblast).
osteo-/ˈɒs.ti.oʊ/
Tap the button to hear how the prefix sounds. Each word in the table has its own audio.
"Osteoporosis" (osteo- = bone + poros = pore + -osis): the bone itself loses mass and becomes fragile, raising fracture risk, often without pain until a break occurs. "Osteoarthritis" (osteo- = bone + arthritis = joint inflammation): cartilage between joints wears down, causing pain, stiffness, and reduced range of motion. Two distinct diseases: one affects bone density, the other joint surfaces.
A trick to remember it
Osteo- = bone. Identical in Spanish: osteoporosis, osteología, osteopatía, osteoartritis. Two key cells: osteoblast (blastos = builder, makes bone) vs. osteoclast (klastos = breaker, dissolves bone). Osteoporosis literally means "porous bones."
Exercise 1 · Form the word
Exercise 2 · Pick the right one
What is the difference between an "osteoblast" and an "osteoclast"?
The prefix osteo- means "bone": osteoporosis, osteology, osteopathic, osteoblast, osteoarthritis. In Spanish it usually maps to osteo-.
The prefix osteo- is pronounced /ˈɒs.ti.oʊ/. For example, "osteoporosis".
"porosis" becomes "osteoporosis". It is a typical example of the osteo- prefix.
un-, re-, pre-, dis-, over-, in-... every beginning you need to unlock thousands of English words at once.