gra·num 
(grānəm)
(grānəm)n. pl. gra·na (-nə)
A membranous structure within a chloroplast made up of stacks of thylakoids.
[Latin grānum, seed; see GRAIN.]
- obstacle
- obstacle course
- obstetric
- obstetrical
- obstetrically
- obstetrician
- obstetrics
- obstinacy
- obstinate
- obstinately
- obstinateness
- obstipation
- obstreperous
- obstreperously
- obstreperousness
- obstruct
- obstructer
- obstruction
- obstructionism
- obstructionist
- obstructionistic
- obstruction of justice
- obstructive
- obstructively
- obstructiveness