grumpyadj (grumpier, grumpiest)

• isochron
• isochronal
• isochronous
• isocline
• isoclinic line
• isodynamic
• isoelectric
• isoenzyme
• isogenic
• isogeotherm
• isogloss
• isogonal
• isogonic
• isohel
• isohyet
• isolate
• isolated
• isolating
• isolation
• isolationism
• isoleucine
• isomer
• isomerise
• isomerism
• isomerize