| economy(performance, energy, skill, readiness, competence) |
| effectiveness(performance, energy, competence, efficacy) |
| effectualness(performance, energy, skill, readiness, competence) |
| efficacy(performance, energy, skill, readiness, competence) |
| effort |
| energy(performance, competence, efficacy, effectiveness) |
| entirely |
| exertion(noun, industry, assiduousness, meticulousness) |
| expertise(skill, readiness, competence, efficacy, effectiveness) |
| facility(skill, readiness, competence, efficacy, effectiveness) |
| faculty(performance, energy, skill, readiness, competence) |
| fairly |
| faithfulness(noun, correctness, precision, accuracy, scrupulousness) |
| faultlessness(noun, correctness, precision, accuracy) |
| fulfiller |
| fuss |
| hairsplitting |
| hardness(severity, harshness, conformity, strictness, conservatism) |
| hardship(severity, harshness, conformity, strictness, conservatism) |
| harshness(severity, conformity, strictness, conservatism, conventionalism) |