• Numerals
• Recent Buddhas
• Sacca / Noble Truth
• Foundation of Mindfulness
• Brahma Vihara Practice
• Guardian deities
• Mahabhuta
• Miscellaneous

Numerals

• Hindu-Arablic numeral : 4
• Roman numeral : IV

Recent Buddhas

• Kakusandha
• Konagamana
• Kassapa
• Gautama

Sacca / Noble Truth

• Dukkha : Unsatisfactoriness / Misery / Suffering
• Samudiya : Cause of suffering
• Nirodha : Cessation of suffering
• Magga : The Path / The Middle Way

Foundation of Mindfulness

• Contemplation of the kaya / body
• Contemplation of the vedana / feeling
• Contemplation of the citta / mind
• Contemplation of the dhamma / general objects — not covered by the above three

Brahma Vihara Practice

• Metta / Loving kindness / Unbounded love
• Karuna / Compassion
• Mudita / Sympathetic joy / Altruistic joy
• Uppekkha / Equanimity

Guardian deities

• Dhatarattha (East)
• Virulhaka (South)
• Virupkkha (West)
• Kuvera (North)

Mahabhuta

• Patthavi / Earth element
• Tejo / Fire element
• Apo / Water or liquid element
• Vayo / Air or wind element

Miscellaneous

• Four sided figures : Rectangle, Square, Parallelogram, Parallepiped, Rhombus
• Baseball : first base, second base, third base, home plate
• Games : Four quarters (e.g. Football, Basketball)
• Rowing : Coxless fours, Coxed fours, Quadruple sculls
• Education : Freshman, Sophomore, Junior, Senior
• April : 4th month of the Gregorian Calendar