In order to provide income over the lifetime of the retiree, the TDF is designed to increasingly invest in deferred annuities as the TDF reaches its target retirement date and investors in the TDF get older.
Freebase(0.00 / 0 votes)Rate this definition: Echocardiography. Echocardiogram, often referred to cardiac echo or simply an echo is a sonogram of the heart. Echocardiography uses standard two-dimensional, three-dimensional, and Doppler ultrasound to create images of the heart.
Full Definition of ECHO. 1. a: the repetition of a sound caused by reflection of sound waves b: the sound due to such reflection. 2. a: a repetition or imitation of another: reflection b: repercussion, result c: trace, vestige d: response. 3. : one who closely imitates or repeats another's words, ideas, or acts. 4.